SANTA CLARA -- Bruce Miller signed a three-year extension Thursday that locks up the 49ers fullback through 2017.
Miller declared himself fully recovered from a fractured left scapula that sidelined him during the 49ers' playoff run to the NFC Championship game.
"It was a struggle standing on the sideline and watching the playoffs, but it's been great motivation for the offseason to get back better than ever," Miller said on a media conference call.
Injured Dec. 15 at Tampa Bay, Miller expects to be "100 percent" cleared for the 49ers' offseason program that begins April 21. His versatility as a lead blocker, short-yardage runner and pass catcher was missed over the 49ers' final five games.
Such attributes weren't on Miller's scouting report coming out of the University of Central Florida. On the eve of the 2011 draft, Miller got a phone call from 49ers running backs coach Tom Rathman that set in motion what's become a prosperous career path.
"It was the first time I heard that was a possibility," Miller said of getting moved to fullback.
After Miller racked up 35½ sacks as a two-time Conference USA Defensive Player of the Year at Central Florida, the 49ers made him a seventh-round draft pick, and he switched to fullback.
"At that point in time, I was really excited about any opportunity to continue playing and moving into the NFL," Miller said. "I didn't care if it was on offense, defense or special teams. It was exciting to know I was on their radar."
Although he had only seven carries for 13 yards last season, he was the 49ers' third-leading receiver with a career-high 25 receptions for 243 yards.
Miller's extension is the latest deal by a 49ers front office that, in recent weeks, also extended fellow 2011 draft pick Daniel Kilgore (a potential starter at center) and re-signed wide receiver Anquan Boldin, kicker Phil Dawson and cornerback Eric Wright. Hammering out an extension for quarterback Colin Kaepernick remains on the team's agenda as he enters the final season of his rookie deal.
"Over the years, we've had a chance to see people's lives change," Boldin said Thursday on NFL Network. "Our mission is to help people that are in need. Where I come from, there's not much opportunity. I try to create opportunity for those that don't have it."
See Cam Inman's Hot Read at blogs.mercurynews.com/49ers.
The 49ers missed the versatility of fullback Bruce Miller (49) over their final five games of last season after he suffered a fractured left scapula against Tampa Bay.