SANTA CLARA — What do you give the running back that can do everything?

If you're the San Francisco 49ers, you give him playing time. Gobs and gobs of playing time.

Six games into the season, the Niners' noted bell cow, running back Frank Gore, appears to be in danger of blowing a tire if his current workload doesn't lessen.

Offensive coordinator Mike Johnson acknowledges the potential for a problem down the road. Gore is on pace for 397 touches this season, a total that would have ranked second in the NFL last year behind Tennessee's Chris Johnson (408). But here's Mike Johnson's problem: Gore is a dynamic runner (second in the NFL with 755 yards from scrimmage), a brilliant pass-catcher (sixth in the NFC with 33 receptions) and his ability to stonewall blitzing linebackers is unparalleled.

Take him out of the game? The Niners are 13-0 when he has 24 carries and 16-6 when he rushes for 100 yards. When he doesn't hit the century mark, they are 16-48. His two lowest rushing totals this season have resulted in the 49ers' only blowout losses — beatdowns against Seattle (31-6) and Kansas City (31-10).

"He's one of our best players," Johnson said. "... I think when he's going, I think our passing game is better. I think when he's going, the line is blocking better and protecting better. He's a big part of what we do and we're happy to have him. I'm glad that he's the kind of player that he is and that he's in the kind of shape that he's in, and that he's the warrior that he is because if he's going, then our offense is going to be pretty good."

Gore ranks second in the NFL in carries (116) and he has the second-most touches (149) behind Johnson (154). Gore has touched the ball on 42 percent of the Niners' offensive plays and accounted for 95 percent of the backfield carries this season. In Sunday's 17-9 win over the Raiders, backups Anthony Dixon (3 carries in 2010) and Brian Westbrook (2) saw about as much time in the backfield as Isaac Sopoaga, a defensive tackle moonlighting at fullback.

Gore doing all the heavy lifting isn't exactly a new storyline. Last year, Gore had 86 percent (228 of 264) of the backfield carries in the 13 full games in which he played. His backup, Glen Coffee, averaged 1.7 carries when Gore played a full game.

The lopsided split is just the way the supremely conditioned Gore likes it. He can take himself out of the game if he gets tired. But he says it's only happened once this year — when he briefly exited during the Niners' 16-14 loss to the Falcons after he ran or caught the ball on five of the previous seven plays.

"I've got to be smart about the situation," Gore said. "I told my coaches that I'll take a breather when I feel like I'm tired. I've been fine lately. I just feel like whenever I'm out there I have a great chance of making plays or we have a great chance to win. So that's probably one of the reasons that I've been out there like that."

This season, the curiously invisible role of Westbrook, who signed $1.25 million contract in August, has caused many to wonder why Gore is assuming all the burden.

Westbrook, who ranks fourth in yards from scrimmage in the NFL since 2004, and Dixon appear quite capable of providing relief. Dixon, a 233-pound rookie who led the NFL in rushing yards during the preseason, has collected a touchdown and two first downs in his three carries this season and looked explosive on a 16-yard touchdown run that was negated by a penalty against the Raiders.

But Johnson said no one can match Gore's ability to pick up blitzes, which, in turn, helps keep quarterback Alex Smith healthy.

Westbrook, a nine-year veteran whom Eagles coach Andy Reid called the smartest player he's ever coached, signed with the Niners nine weeks ago. Johnson indicated Westbrook is still not fully up to speed on the 49ers' protection schemes. Still, he understands the 49ers need to entrust others with Gore's duties, or risk losing him to overuse.

"It's a comfort zone for us coaches as well," Johnson said. "But we do have to find ways to make sure that we get him some rest."


Defensive coordinator Greg Manusky, who was Shawne Merriman's position coach in San Diego from 2005-06, was asked Thursday about the possibility of the Niners claiming the former All-Pro linebacker at some point this season.

"I don't know. We'll see what happens," Manusky said. "I don't know what's going on. I don't know what the scenario is down there in San Diego. He was a fine player when I had him and he's been banged up a little bit, I know that."

The Niners reportedly have interest in claiming the 6-foot-4, 265-pound Merriman, 26, once he's released by the Chargers. ESPN's Adam Schefter reported that San Francisco even had an interest in trading for Merriman before San Diego decided to release him. Merriman, who has a calf injury, must pass a physical before San Diego can release him.

The injury-plagued Merriman has started just 16 games and has four sacks since 2008. He had 27 sacks in the two seasons with Manusky.

"When I had Shawne, he was a great player," Manusky said. " ... I loved everything about the kid."

CB Nate Clements (ankle) did not practice Thursday. Will James would likely start if Clements can't play Sunday at Carolina.

For more on the 49ers, go to Instant 49ers at blog.pressdemocrat.com/49ers. You can reach Staff Writer Eric Branch at eric.branch@pressdemocrat.com and follow him at twitter.com/Eric_Branch.