Early in Rock Cartwright's NFL career, it seemed every year he was on the bubble for a roster spot.
Not anymore. Barring something unforeseen, Cartwright should secure his standing as a kick returner and special teams player when the Redskins.
That means Marcus Mason, the second-year roster hopeful, is competing for a roster spot as a fourth running back.
The Redskins must make final roster decisions by Saturday, Aug. 30, at 6 p.m. ET.
Mason was on the Redskins' practice squad last season. He led the team in rushing this preseason, with 317 yards on 66 carries. He also had eight catches for 56 yards and one touchdown.
Cartwright has helped Mason along the way, knowing full well that Mason would like to be in his shoes.
"There is always somebody out there trying to get your position and take your job so you can never relax in this business," Cartwright said. "But I'm all for the team. If I can help a guy that's going to help us win football games, then that's what I'm going to do.
"Marcus is doing a great job right now and I'm happy to help him out if I can. When I was a rookie [in 2002], Stephen Davis took me under his wing and showed me what to do and what not to do, and how to practice as a pro. I was fortunate."
Cartwright, a seventh-round draft pick in 2002, is in his seventh season now. He serves primarily on special teams, something that Mason and other young players must do to earn a roster spot.
Cartwright has a 23.9-yard kickoff return average in his career, and he also has 102 career special teams tackles. His 3,157 career kickoff return yards ranks fourth all-time in franchise history.
He excels at special teams because he knows opportunities at running back are limited.
"In this offense, with Clinton Portis and Ladell Betts, you're not going to get many carries," Cartwright said. "The only way to get on the field is special teams and I take pride in that. Marcus is doing the same right now. It's a positive thing."
In preseason, with Portis and Betts getting limited action, Cartwright has had 20 carries for 158 yards. He had a 73-yard run in the Redskins' 13-10 win over the New York Jets on Aug. 16.
Cartwright sat out the Jacksonville preseason finale for some rest. He was slowed by a rib injury early in preseason, but he missed just one of the Redskins' first four games.