SANTA CLARA, Calif. -- Given how banged up the San Francisco 49ers have been this summer, it's clear their offensive success will revolve heavily around Vernon Davis this fall.

He's their Pro Bowl-caliber tight end and a legitimate game-changer. He's also the player who came up huge in the postseason two years ago, when his game-winning catch beat the New Orleans Saints in the NFC divisional round. Most importantly, Davis is the person the 49ers are asking to make the biggest transition this coming season.

Ask Davis what this year's training camp has been like and he'll say his head has been spinning from all the preparation. The 49ers are asking him to learn plays for both wide receiver and tight end this year, because injuries have ravaged the receiver position. Michael Crabtree, who led the team in receptions last season, is sidelined with a torn Achilles while Mario Manningham is recovering from a torn anterior cruciate ligament. If that wasn't bad enough, four other receivers recently sustained injuries, prompting the team to sign free agents Austin Collie and Lavelle Hawkins.

Regardless of how quickly those newcomers assimilate -- or how quickly Crabtree and Manningham can heal -- San Francisco's best hopes for a viable passing game once again rest with Davis, a player who has been the team's most capable target for most of the past few years.

Colin Kaepernick didn't target Vernon Davis as much as Alex Smith did, but that could change this year. AP Photo/Tony Avelar

"I've never had to spend as much time in the playbook as I have this training camp," Davis said. "I hope they're planning on using me at wide receiver because I've worked pretty hard learning to do it."

Davis' adjustment is vital to the 49ers because Crabtree meant so much to this offense during his breakout season in 2012. Crabtree set career highs in receptions (85), yards (1,105) and touchdowns (nine) while emerging as the favorite target of quarterback Colin Kaepernick. As Kaepernick blossomed into a star, it became apparent that he would look for Crabtree in the most critical of situations. It's no coincidence that the quarterback targeted Crabtree on the pivotal fourth-down incompletion that decided last year's Super Bowl loss to the Baltimore Ravens.

The 49ers tried to deepen their receiving corps this offseason by trading for former Ravens receiver Anquan Boldin, but that move sounded better when Crabtree was healthy. Boldin never caught more than 65 passes or produced a 1,000-yard season during his three years in Baltimore. While most people remember his heroics in the midst of the Ravens' Super Bowl run a few months ago, those same optimists likely forget Boldin turns 33 in October and is a long way from his Pro Bowl years in Arizona, when he averaged 84 receptions over seven seasons.

The 29-year-old Davis, on the other hand, is still in his prime and capable of making the transition the 49ers are seeking. He's always had breathtaking speed, and his hands have improved over the years -- along with his feel for how to set up defenders. When Mike Singletary was coaching the 49ers, he suggested the possibility of moving Davis out wide to create mismatches. It was one of the few intriguing ideas Singletary produced during his tenure with the franchise.

There's little doubt that Davis would be comfortable matching up against cornerbacks and safeties when split out wide. The major issue is finding a comfort level with all the demands of the position.

"I played some wide receiver in high school, but it was nothing like what they're asking me to do at this level," he said. "You're talking about more complicated routes, a better understanding of coverages, a lot of things that take some time to develop."

The good news for the 49ers is that Davis has always liked a challenge. He values his role as a leader and has never shied away from the spotlight. The main reason he enjoyed such a spectacular run in the 2011 postseason -- when he had 10 receptions for 292 yards and four touchdowns -- was because he wanted that pressure laid on his shoulders. He knew that was his time to shine.

Davis has that same desire during this training camp. He enjoyed a strong Super Bowl performance (six receptions, 104 yards), but his regular-season numbers (41 receptions, 548 yards, five touchdowns) were the lowest they had been since 2008. Crabtree's explosion is one way to explain that decline in production. Another is to say that Kaepernick didn't rely on his tight end as often as his predecessor, Alex Smith, did.

That's all about to change this season. As talented as Kaepernick is, he's not going to dominate so easily without a dangerous downfield threat. Opposing defenses will stack the line of scrimmage and pummel him any time he decides to carry the football. The 49ers will have to take pressure off him by stretching the defense. That is a skill that Boldin has never supplied during his career, not even when he was at his best.

So Davis will have to cram, catch up and keep himself from going crazy learning all the subtleties that will come with his new role. In many ways, he'll be asked to do the things that have made other tight ends -- namely San Diego's Antonio Gates, Atlanta's Tony Gonzalez and, more recently, New England's Rob Gronkowski -- so successful. It's not just about whether he can be comfortable playing wide receiver occasionally this year. It's about whether he can get back to the place he was at during the end of the 2011 season, when everything about the 49ers' passing game revolved around his impressive talents.