SANTA CLARA, Calif. - Kevan Barlow is done sharing the ball.
After three years in an uncomfortable partnership with Garrison Hearst in the San Francisco 49ers' backfield, Barlow will be the full-time starter this season. The team allowed Hearst to leave for Denver shortly after signing Barlow to a five-year, $20 million contract in February.
''I'm ready. I've been looking forward to this challenge since I've been here,'' Barlow said. ''I've been scratching for three years now, and it's finally here. I feel more comfortable that the team has confidence in me.''
But Barlow hasn't relaxed just yet. His coaches believe he worked harder than ever this summer to build muscle and flexibility - even studying kickboxing on a tip from Baltimore's Jamal Lewis.
''He said he did the kickboxing thing last year and got 2,000 [yards],'' Barlow said. ''I just said, 'Hey, I'm going to do it, see if I can get 2,000, too.' ''
The 49ers' rushing game traditionally was one of the NFL's most effective during two decades running the West Coast offense. Now that San Francisco's offense is a collection of largely unknown youngsters running a hybrid scheme, Barlow just might be the most important part.
And that's fine with Barlow, who has boosted his rushing total in each of his three pro seasons. He started the final four games of last season, finishing with 1,024 yards and six touchdowns.
The 49ers paid top dollar to keep Barlow, who attracted interest from several teams in possible trades last season. After a productive offseason, coach Dennis Erickson believes Barlow is just about to hit his stride as an elite NFL running back.
''When you know you are the guy, it's a little bit different mind-set for you,'' Erickson said. ''He's worked hard to be the guy, and it's showing so far.''
Barlow will run behind Pro Bowl fullback Fred Beasley, and their antagonistic relationship seems more mellow after the departure of Hearst, Beasley's close friend. Barlow and Beasley barely spoke in previous seasons, nearly coming to blows at least once.
But if they're getting along, Barlow and Beasley could be one of the league's top backfields. San Francisco's offensive line seems better suited for run-blocking this year, with mobile youngsters Kwame Harris and Justin Smiley likely to take big roles next to the returning veterans, including center Jeremy Newberry.
''If they depend on me, that's good,'' he said. ''When we have to run it, I'm willing to run the ball how many times it takes.''
Barlow doesn't believe most predictions about the 49ers, who will have at least seven new offensive starters and two new coordinators on a team that went 7-9 last season. Despite the departures of Terrell Owens, Jeff Garcia, Hearst and Tai Streets, Barlow is optimistic.
''We're going to be a force to be reckoned with,'' he said. ''I think a lot of teams are going to underestimate us.''