Turns out Rossum is doing a whole lot more.

After coordinator Mike Martz got a look at the 5-foot-8 veteran's speed when Rossum returned a punt 67 yards for a score in the preseason against Green Bay, he enlisted Rossum to learn a few trick plays for the San Francisco offense.

His moonlighting career took off last month against Detroit when he took a handoff on an end-around and dived into the end zone for a 1-yard run - the eighth score of his career, but the first that didn't come on a kick return. Rossum again was on the field last week against Philadelphia, faking runs and catching passes.

Though Martz hasn't used him as more than an occasional novelty, the extra work is a thrill for a player who's never hesitated to try new things.

"I just love playing the game, and it doesn't matter how long I've played or how much I've achieved," said Rossum, who's in his 11th NFL season with his fifth team. "I love getting the opportunities I'm having over here, but I'd take on any role and do really anything they ask me, offense or defense or my specialty."

Rossum also has been solid in his regular role on the 49ers' special teams, which are playing well despite the slumping club's 2-4 record heading into Sunday's game at the New York Giants.

He's 10th in the NFL with 26.3 yards per kickoff return, and his 20.8 yards per punt return would be second in the league if he had enough returns to qualify.

Rossum's speed was irresistible to Martz, who has had a short-statured burner among his options at receiver on his last two teams: Mike Furrey and Shaun McDonald in Detroit, or Kevin Curtis and Az-Zahir Hakim back in St. Louis.

"I just thought, 'If he's going to be on our roster as a specialist, we could sure use him potentially on offense,"' Martz said. "With his open-field abilities, we were excited about doing so. If gives you another playmaker on the field, even if it's a couple or three times a game. That puts stress on the defense, and that's what you're trying to do."

Rossum also is listed on the 49ers' roster as a cornerback, and he has started nine NFL games on defense. Though he has the credentials to be a two-way player, Rossum knows he'll only stay in the league if he remains focused on his kick return duties.

He's been a consistent, productive returner ever since he joined Philadelphia as a third-round pick from Notre Dame in 1998, yet he knows most teams prefer young speedsters who play other positions to fill that role. But he attracted the 49ers' attention last fall with a 98-yard kickoff return for a touchdown against them during an otherwise unremarkable season with Pittsburgh, and San Francisco signed him in the offseason.

Rossum began the season second in NFL history in total return yards and kickoff return yards. During his five seasons with Atlanta, he also forged a friendship with Billy "White Shoes" Johnson, the famed receiver and returner for the Houston Oilers and Falcons.

"You've got to be confident you're going to make the right decision, and then if you're wrong, you've got to live with that," Rossum said of White Shoes' lessons. "It's really about being confident in your abilities, and that's what I've been working toward my whole career."