Mike Shanahan and the Redskins are going for their sixth win of the season. (Photo: Heather Farrell)

A costly block in the back, a failed defensive stand with less than two minutes left and more third-quarter woes for the Redskins' offense all combined for the makings of a 17-13 Minnesota Vikings victory at FedEx Field.

The Washington Redskins came up short once again in another game they should've won. A block in the back by rookie linebacker Perry Riley during an 77-yard Brandon Banks punt return nullified Banks' potentially game-winning touchdown. The offense failed for a fifth time in the second quarter to convert a third down. Then the defense let Brett Favre & Co. march downfield and milk the clock. The clincher was Favre scrambling 10 yards for a first down to put his team in victory formation with no timeouts left.

The Redskins fall to 5-6 and likely say good-bye to their playoff hopes.

Update 3:50 p.m. -- Definitely not the first full-time showing the rookie linebacker Perry Riley wanted.

Riley has been inactive for all but two games this season, and got the nod for a third appearance today with other linebackers playing with injuries.

Riley was in on special teams and has definitely had an impact -- negative that is -- for the Redskins.

First, his block in the pack on a Brandon Banks punt return backed Donovan McNabb & Co. up to the shadow of their goal line and on first-and-10 from the 5 yard line, Santana Moss let a pass go through his hands and off his facemask and Minnesota linebacker E.J. Henderson intercepted it. The Vikings scored a field goal to go up 17-7.

Washington still had hope, however. With just more than seven minutes left, Banks ripped off an 77-yard punt return for a touchdown . . . but Riley was called for yet another block in the back, taking the seven points -- seven points that would've put Washington up 20-17 -- off the board.

The Vikings went on to win 17-13.

Of course, Riley wasn't totally to blame, and yes, he'll be on the team. There were plenty of other breakdowns that also proved costly in this latest Redskins loss.

The defense let Toby Gerhart run over them for key gains, and the offense couldn't buy a second-half third-down conversion. Donovan McNabb underthrew Anthony Armstrong on what would've been a touchdown pass, but instead only set up a field goal. And the defense let Brett Favre roll out and run for 10 yards and a first down right after the two-minute warning.

The Redskins had their chances indeed. Instead of pulling out a win and keeping playoff chances alive, they're basically done for the year after falling to 5-6 thanks to this 17-13 loss.

Update 3:28 p.m. -- The Redskins have put more points on the board, but once again, not as much as they had had the potential to score.

Donovan McNabb had Anthony Armstrong streaking up the left sideline with a step on his man, but the QB's throw was short, and instead of catching the ball instride and trotting into the end zone, Armstrong had to come back for it and make a sliding catch.

The 45-yard pass (which gave Armstrong his eighth-consecutive 40-plus yard receiving game) put Washington on the Viking 24-yard line. A dropped pass by Armstrong, another underthrown ball by McNabb and a deflected pass later, Gano made a 42-yard field goal. Minnesota 17, Washington 14 now with just more than eight minutes left.

Update 3:25 p.m. -- The Redskins couldn't capitalize on a short field as much as they should have. Instead of cashing in on a 65-yard kick return to the Minnesota 28 from Brandon Banks, they had to settle for a field goal after failing again to convert on third down.

The Redskins are within a touchdown of tying the Vikings, so that's good news. But the bad news is they are 1-for-8 on third downs in the second half.

Graham Gano made a 40-yard field goal after Keiland Williams was stopped three yards shy of the first-down marker on a catch from McNabb.

Update 3:10 p.m. -- The Redskins find themselves down 17-7 now thanks to an interception by E.J. Henderson at Washington's 9-yard line. But as has been the case this game, Donovan McNabb's receivers are more to blame for Washington's ineffectiveness than he is.

This time, with the Redskins backed up at their own 5-yard line thanks to a block in the back call on Perry Riley in punt coverage, McNabb passed to Santana Moss in the flat. But the receiver let the ball go through his hands and it then bounced off his facemask, up into the air and down into Henderson's waiting arms. It was a big moment for the former Terp, who before the game came out of the tunnel and yelled to the fans, "THIS IS MY CITY!"

Give the defense props for holding the Vikings to a field goal, however.

The Fourth quarter just opened and Washington has the ball on the Minnesota 26-yard line after Brandon Banks returned the kick 65 yards to give his team a short field. We'll see if they can do anything with it.

Update 2:42 p.m. -- The Vikings ended their scoring drought by marching downfield at the start of the second half and finding the end zone on a five-yard run from Toby Gerhart.

Brett Favre has found a hole in the right side of the field and has repeatedly gone to a roll-out and connected with whatever receiver he wants. He just went 5-for-5 passing on the nine-play, 74-yard drive.

The big play of the drive was a 29-yard throw deep right to Visanthe Shiancoe that put the ball at Washington's 14-yard line. Favre again rolled out to his right and Shiancoe had blown past Carlos Rogers, who had no safety help over the top.

The Redskins had their safeties cheated up often, and got burned for it.

Adrian Peterson hasn't returned, but the Vikings don't need him. Gerhart is running hard and getting extra-effort yards.

The Redskins couldn't respond on offense. Donovan McNabb was under pressure on ever drop-back of the first third-quarter series, and he and his offense went three-and-out.

Update 2:20 p.m. -- It's halftime here at FedEx Field and the Washington Redskins and Minnesota Vikings find themselves in a 7-7 tie and operating at a much slower pace than they were when they opened the game with back-to-back scoring drives.

After two quarters, the Redskins have outgained the Vikings 150-135 on offense. Washington has 128 passing yards and only 22 rushing yards. Meanwhile, Minnesota has 76 passing yards and 59 rushing yards.

After opening the game with a 8-for-8 passing performance, Donovan McNabb has gone 5-for-11 since and isn't getting nearly as much time as he was at the start of the game. The Vikings are hitting the Redskins with more stunt blitzes to keep the offensive linemen off-balance.

Working in favor for Washington's defense is the fact that they knocked Adrian Peterson out midway through the second quarter and he has yet to return.

Update 1:57 p.m. -- The Redskins defense just forced another Viking punt after a big stop by London Fletcher.

On third-and-1, Albert Haynesworth shot the gap and forced running back Toby Gerhart to change directions, and Fletcher met him for a tackle in the backfield.

The Redskins' defense might have handed the Vikings a more crushing blow two plays before that, though. Adrian Peterson limped off with what appears to be an injury to his right ankle. If he can't return, this game changes dramatically.

Update 1:49 p.m. -- After both teams stormed out of the gates with scoring drives, each team's defensive unit decided to show up and force punts.

The Redskins went three-and-out after a disjointed possession that featured a timeout to avoid a delay of game call, and poor pass protection from the offensive line.

The Vikings got two first downs on their second possession of the game, but then hit the wall. On that series, Brian Orakpo recorded a sack, bringing his season total to 8.5. He becomes the first Redskin to record at least eight sacks in consecutive seasons since Ken Harvey did so in 1996 and 1997.

Washington had to punt on their third possession of the game as well. But don't blame the line or McNabb this time. The quarterback hit Chris Cooley and Santana Moss in the hands on passes that would've gone for first downs, but they both dropped the ball.

Update 1:26 p.m. -- The Washington Redskins just opened this game against the Minnesota Vikings with a surgical scoring drive that was capped by a 10-yard touchdown catch by tight end Fred Davis from Donovan McNabb.

Kyle Shanahan had a great play-calling game last week against the Tennessee Titans and it appears that he has picked up right where he left off.

The Redskins threw all kinds of new wrinkles out there as they carved up the Vikings. There was the traditional handoff to Keiland Williams, an option-style quarterback keeper in which McNabb scrambled for three yards and a first down. There was Brandon Banks lining up in the Wildcat formation twice (and McNabb split out as a receiver) and both times went for three-yard runs.

And through the air, McNabb was a perfect 8-for-8 for 84 yards, going to five different receivers, including the seldom-used Roydell Williams for a 19-yard catch-and-run.

Davis hasn't been used nearly enough as a receiver, but McNabb went to him for a 10-yard fade route, and the USC product made the grab for his first touchdown of the game.

David Aldridge and I were just talking before the game, wondering why the Redskins don't use more two tight-end sets with either Cooley or Davis split out wide given the lack of size Washington has at receiver. Obviously, Kyle Shanahan had the same thought this week as the Redskins used that look twice in the opening drive.

But not to be outdone, the Vikings answered right back with a scoring drive of their own. Needing just seven plays to go 71 yards, Minnesota road Adrian Peterson to paydirt. Peterson ripped off a 34-yard catch-and-run on a screen pass on the Vikings fourth play. Three plays and several broken tackles later, Peterson scored from five-yards out.

Stay tuned . . .

Published 11:58 a.m. -- Good morning from FedEx Field where the Washington Redskins in just a bit will take on the Minnesota Vikings in search for their sixth win of the season.

The inactives for this game have been announced, and Redskins safeties Macho Harris and LaRon Landry, running backs Ryan Torain and Andre Brown, left guard Derrick Dockery, defensive linemen Jeremy Jarmon and Anthony Bryant all will not suit up today. John Beck will be the emergency quarterback.

Few names on the list are a surprise considering Landry, Torain, Jarmon and Dockery all have been either limited or sidelined completely with injury in the last week of practice.The inactivity of the newly-signed Harris is a little surprising because of the fact that the Redskins are so thin at the safety position. But it likely is a sign that cornerback Kevin Barnes can better help the Redskins filling in at safety because he has been in this system all year long while Harris is still learning it.

The only reported changes in the starting lineup are at running back (Keiland Williams) and strong safety (Reed Doughty). That must mean that Santana Moss (knee), center Casey Rabach (knee) and right guard Artis Hicks (thigh/groin) will start after being limited in practice this week. Starting despite being knocked out of last week's game are linebackers Lorenzo Alexander (hamstring) and Rocky McIntosh (thigh). Also active a week after being out with injury is cornerback Carlos Rogers (hamstring).

Look for newly promoted wide receiver Terrence Austin to get a fair amount of activity today, however, given the fact taht Moss isn't 100 percent and neither is kick/punt returner Brandon Banks.

Check back right here throughout the game because this is your spot for in-game analysis and developments. Also join in for TBD's in-game chat where you can sound off on the the Redskins as they battle the Vikings.