--RB Ladell Betts is out with a sprained knee for the third straight week.

--CB Shawn Springs is out with a strained calf for the third straight week.

--WR Malcolm Kelly is out with an ailing left knee for the third straight week.

--OT Chris Samuels (knee) returned on Wednesday after sitting out at Detroit.

--S Chris Horton (ankle) returned on Wednesday after sitting out at Detroit.

--DT Cornelius Griffin (shoulder) returned on Wednesday after sitting out at Detroit.

--DE Jason Taylor (calf) didn't practice and is doubtful for Monday's game with Pittsburgh.

--RB Clinton Portis (hip, ankle) didn't practice on Wednesday but is expected to start on Monday.

--WR Santana Moss didn't practice on Wednesday but is expected to start on Monday.

--G Pete Kendall (knees) didn't practice on Wednesday but is expected to start on Monday.

--CB Carlos Rogers (calf) didn't practice on Wednesday but is expected to start on Monday.

--FS LaRon Landry (hamstring) didn't practice on Wednesday but is expected to start on Monday.

--KR Rock Cartwright (knee) didn't practice on Wednesday but is expected to play on Monday.

GAME PLAN: The Redskins have been rolling on the ground for weeks, but they haven't run up against a run defense like that of the Steelers. Pittsburgh allows just 72 rushing yards a game. Elite backs Brandon Jacobs, Fred Taylor, Maurice Jones-Drew, Willis McGahee, Jamal Lewis, Steve Slaton and Brian Westbrook have all struggled against the Steelers' 3-4 defense. Linebackers James Farrior, Larry Foote and James Harrison are all strong tacklers as is Pro Bowl safety Troy Polamalu. So this game is all on the Redskins' offensive line and fullback Mike Sellers being able to open holes for Portis and to give quarterback Jason Campbell time to find Santana Moss and Co. downfield. Pittsburgh has 25 sacks.

Washington's defense doesn't face as big a challenge as its offense. Pittsburgh's usually potent ground game has been hamstrung by the loss of Pro Bowl guard Alan Faneca to free agency as well as injuries to No. 1 back Willie Parker, left tackle Marvel Smith and right guard Kendall Simmons. Hence, quarterback Ben Roethlisberger has been sacked 23 times. Since the Redskins have managed just 10 sacks, look for coordinator Greg Blache to try to create some pressure with blitzes, trusting his secondary -- led by rising cornerback Carlos Rogers -- to cover Steelers receivers Hines Ward, Nate Washington and Santonio Holmes. Middle linebacker London Fletcher leads Washington's fifth-ranked run defense.

MATCHUPS TO WATCH: Redskins MLB London Fletcher vs. Steelers RB Willie Parker -- Fletcher has 69 tackles, 17 more than any other Redskin. His 40 solo stops are more than all but two teammates' total tackles. The 33-year-old veteran, who roams the field to make plays, also calls the defensive signals and is the sixth-ranked unit's holler guy. Fletcher's three tackles for losses are also tied for a team-high. The speedy Parker, who ran for 4,000 yards the past three years, gained 243 yards the first two games before injuring a knee in Week 3. As well as Mewelde Moore has played, the Steelers are definitely better if Parker returns, as expected for Monday's game. Left tackle Marvel Smith could also be back for the Redskins.

Redskins RB Clinton Portis vs. Steelers run defense: Portis, who leads the NFL with 944 rushing yards -- 260 more than his nearest pursuer, Minnesota's Adrian Peterson, can join Hall of Famers Earl Campbell (1980) and Eric Dickerson (1984) as the only backs with at least 120 yards in six straight games. It's no coincidence that Portis' production skyrocketed as soon as Jon Jansen replaced Stephon Heyer at right tackle in Week 4. If Pro Bowl left tackle Chris Samuels returns to the lineup, after missing last week's game at Detroit, the Redskins will be better equipped to handle the physical and aggressive 3-4 defense of longtime Steelers coordinator Dick LeBeau. With safety Ryan Clark doubtful, linebacker James Farrior is clearly Pittsburgh's top tackler.

INJURY IMPACT: With Ladell Betts (knee) out again, Shaun Alexander backs up NFL rushing leader Clinton Portis.

--With left cornerback Shawn Springs (calf) out again, Fred Smoot would start with Leigh Torrence moving up to No. 3 and rookie Justin Tryon to No. 4.

--If left defensive tackle Cornelius Griffin (shoulder) can't play again, Anthony Montgomery, a regular in 2007, would make his second straight start.

--If left defensive end Jason Taylor (calf) misses a third game this season, Demetric Evans would start for him again.

--If receiver Santana Moss (hamstring) misses his first game of the year, James Thrash would start in his place.

--If left tackle Chris Samuels (knee) misses a second straight game, Stephon Heyer would start again in his place.

--If strong safety Chris Horton (ankle) misses a second straight game, Mike Green would start again in his place.