Frank Gore, who turns 30 next month, did not slow down last year from a production standpoint.

Gore has rushed for more than 1,200 yards in back-to-back seasons -- his two highest totals since his team-record-breaking 1,695 yards in 2006, his second year in the NFL.

The 49ers had one of the league's top ground games in 2012, ranking fourth in rushing yards per game (155.7) and third with a 5.1-yard average. It did not hurt that the 49ers have a quarterback, Colin Kaepernick, who can chew up huge amounts of yards on the ground. The running back will continue to be a huge part of this team's offense because of a young and powerful offensive line.

The 49ers always want to have a stable of running backs and general Trent Baalke intimates that a shift to more of a backs-by-committee approach could be in the team's future.

"I'm a big believer -- we are big believers -- in a three-headed approach," Baalke said last week. "In other words, having a group of backs that bring to the table something a little bit different than the other one so you can do a lot of different things. But also having those backs be able to do enough things the same so you don't become so predictable on game day."

Kendall Hunter returns from season-ending surgery to repair a partially torn Achilles tendon. He is expected to be ready for the opening of training camp to resume his job as Gore's primary backup. LaMichael James was also an effective runner when he became the backup to Gore after Hunter's injury.