"Because of new strength coach Rock Gullickson, Steven Jackson reports that he's "definitely stronger now." Because of new running backs coach Sylvester Croom, Jackson says he's "actually understanding the details on (running a pass) route."

Which all figures into Jackson's ultimate goal.

"I'm working on being a complete running back," he said. "I've said that in the past, but this year I'm really getting detailed coaching."

For the West Coast-style offense that coordinator Pat Shurmur has installed to perk smoothly, Jackson will have to carry a big load, both as a runner and receiver.

Just three years removed from leading the NFL in yards from scrimmage, Jackson is seeking to prove his durability while also ratcheting up his productivity.

Not that Jackson hasn't produced: He topped the 1,000-yard rushing mark in 2007 (1,002) and '08 (1,042). But his receiving totals dipped significantly from '06, when he caught 90 passes for 806 yards to go with his 1,528 yards on the ground.

That's partly because a groin tear kept him out of four games in 2007, and he again was limited to 12 games last year because of a thigh injury.

"Of course, I want to be healthy, but I don't think it's really something you can prepare for," Jackson said. "A torn groin or a torn hamstring, it just happens."

Solid preparation, though, is no accident. That's where Croom's influence is making a difference, Jackson said.

"He's really big on making sure you understand; he's a teacher," he said. "Some things that you feel like you know, he double-checks you. He's a guy that come September ... I'm going to be coached up enough that I'm going to know my responsibilities, I'm going to know my assignments so I'm able to play fast.""