At some point in almost every game, Washington Redskins running back Clinton Portis is hobbled on the sideline, receiving medical attention as he attempts to shake off another huge collision with a much heftier opponent. That pain comes naturally to those who carry the football in the NFL -- the talent that earned Portis one of the bigger contracts in league history last year -- but more often than not those injuries occur from performing less rewarding and more overlooked duties.

Portis's 27 carries for 136 yards during Sunday's victory in St. Louis captured headlines, but what had his coaches and teammates raving was his willingness to protect quarterback Mark Brunell on pass plays. The abandon with which Portis plays -- despite a frame listed generously at 5 feet 11, 211 pounds -- has won the respect of his bosses and peers. Portis might never come close to duplicating the eye-popping statistics from his two seasons in Denver, or run over defenders the way some featured runners did in Coach Joe Gibbs's Super Bowl backfields -- and his wacky costumed weekly news conferences surely rub some the wrong way -- but the desire and selflessness with which he plays have made him a favorite at Redskins Park.

"His second effort in the way he chases things and tries to help other people or what have you, I think it's rare," Gibbs said. "And it's phenomenal to watch him play like that and he plays so hard. He's a physical guy, and most of the time he comes across to you personality-wise as always joking about this or that, or saying he wants to get out of practice today or whatever, but his mentality once the game starts, he's an aggressive sucker, and he goes hard."

During his Hall of Fame career, Gibbs said he has seen few top running backs who are as willing as Portis to share the ball, block and do other things. The staff expects to lean heavily on Portis during these final four crucial games -- including Sunday's game in Arizona against the league's worst defense against the run -- and Portis said his body is better conditioned to withstand that load than it was last year, even after battling through a continued battering Sunday.

Portis was knocked out of last weekend's game after throwing himself in front of tackle Damione Lewis, a 6-foot-2, 301-pounder who, like Portis, attended Miami. Portis caught the wrong end of the contact in his cutback block -- "I'm throwing 210 [pounds] and [he's] 300, so you know it's going to be tough" -- then, after "clearing the cobwebs," he re-entered the game one series later. A week earlier, Portis delivered a massive blow to San Diego linebacker Steve Foley (6-4, 265 pounds), catching him on a pass rush and flipping him head over heels to the grass.

"He's a mean dude," Joe Bugel, assistant head coach-offense, said of Portis. "He'll attack you. You don't have to worry about him holding the flank and blocking for our receivers. I'll tell you what, he's the best without the football we've had. When he doesn't have the ball, he's a raving maniac, and you don't see that too much in the NFL."

Offensive coordinator Don Breaux said: "I've never been around a tougher person as a running back, and he does things no other backs in this league do. He's an excellent blocker, and he doesn't try to size up who he's going to hit, believe me. He doesn't just pick on DBs [defensive backs], he goes after anybody."

In October, Denver linebacker Al Wilson (6 feet, 240 pounds) sprinted untouched up the middle of the field, bearing down on Brunell, and Portis darted over and took the full brunt of the blow -- and was knocked from the game for a spell -- but allowed the passer to release the ball in good health.

"My bell is often wrung," said Portis, who adopted the character "Kid Bro Sweets" for yesterday's press gathering, including a yellow wig, rotten false teeth and gold, heart-shaped sunglasses. "It's just doing whatever it takes, man. I don't want Mark walking around here looking like this."

Some maintain Portis is not a great fit for Washington's power running game, but when he meets with running backs coach Earnest Byner each week to discuss his favorite plays, Portis invariably asks for more inside calls. Byner said the coaches have implemented four new outside runs involving cutbacks similar to what Portis capitalized on in Denver, but he is equally excited to run between the tackles and loves following H-back Mike Sellers as a lead blocker.

"Earnest brings the list to Joe and us each week and we try to accommodate them," Bugel said. "And believe it or not Clinton Portis likes the inside runs for some reason. He'll run the stretch plays good, but he likes isolation and meat-and-potato type plays."

Portis admits he wore down in the second half last season. He was not carrying as much weight and did not fully participate in the club's offseason workout program. Portis finished with 1,315 yards, but had a weak 3.8-yard average per carry, well below the NFL average and nowhere near his 5.5 average in Denver. Portis also scored just five rushing touchdowns, a third of his seasonal output with the Broncos.

"Last year, I think I was beat down," Portis said.

This season, he has averaged two fewer carries per game, and was spelled considerably more in the early months, with his workload growing as the weather has turned colder. Portis ran 29 times against San Diego and 27 times against St. Louis -- his highest totals of the season -- and is fourth in the NFC with 1,079 rushing yards, on pace to surpass 1,400. He is averaging a solid 4.3 yards per carry with seven touchdowns, and feels he is primed to peak down the stretch after bulking up considerably in the summer and averaging 115 yards in his past four games.

"From the beginning of the season, I've been enduring for this stretch," Portis said. "We've got four games left, and whatever is asked of me, I'm ready. Last year, I couldn't have taken this challenge. You notice my carries have been up the last few weeks and if it continues to go up or if it stays where they're at, I'm prepared for that."

Clinton Portis, right, sent the Chargers' Steve Foley flying to help protect Mark Brunell, left. "He's a mean dude," assistant Joe Bugel said of Portis.