San Diego ? How badly does it hurt the San Diego Chargers when LaDainian Tomlinson can’t carry the ball full time?

Jesse Chatman has quickly answered that question: not at all.

Chatman used to have one of the NFL’s most obscure jobs until Tomlinson strained his groin four weeks ago. Since then, there’s been little dropoff when the obscure substitute replaces the superstar for the surprising Chargers (4-3).

Given the most extensive playing time of his three-year career, Chatman has broken long runs and scored big touchdowns in the last four games.

He’s certainly put the Chargers at ease.

“I’m pretty sure all of us worry about what happens if L.T. goes down,” Chatman said. “Right now with the little opportunities I’m getting, hopefully I’m calming those worries down, if he does go down, that I want them to know that I’m able enough to step in and take care of the job.”

Tomlinson was hurt in the second half of a home victory over Tennessee on Oct. 3, finishing with 147 yards and one touchdown. He’s started the last three games and scored a touchdown in each, but failed to crack 65 yards in any of them and made way for Chatman several times.

With his groin acting up Sunday and the Chargers leading Carolina by four points, Tomlinson told the coaches he felt Chatman would be more effective in the fourth quarter. Sure enough, Chatman rambled 52 yards just before the 2-minute warning, then scored on a 5-yard run to clinch the 17-6 victory.

“I can’t think of a guy that’s a backup that may be better than him in the National Football League,” Tomlinson said. “He’s done a tremendous job. Jesse has a lot of talent.”

That’s pretty good praise for a guy who joined the Chargers as an undrafted rookie from Eastern Washington in 2002. Until now, his best games were during the exhibition season, when there’s no need for the Chargers to play Tomlinson.

Chatman was consigned mostly to special teams in his first two seasons and had only 14 carries for 36 yards, and eight catches for 98 yards.

Since Tomlinson got hurt, Chatman has taken advantage of his chances, gaining 207 yards on 25 carries, with three touchdowns.

At 5-foot-8, 247 pounds, Chatman is 2 inches shorter and 26 pounds heavier than Tomlinson. He’s more of a straight-ahead runner, but has some moves, too.