SANTA CLARA (AP) — Michael Crabtree smiled, took a breath and tried to explain how his latest injury happened. After a few silent seconds, the San Francisco 49ers wide receiver finally gave up.

"I don't know too much about injuries, bro. You would think I would know," he said, laughing.

Maybe nobody with San Francisco should know more.

Speaking publicly for the first time since January's NFC championship game, Crabtree said Tuesday that his strained right calf — an injury that had been a mystery to everybody outside the 49ers locker room — won't sideline him for San Francisco's preseason opener Friday night against the Minnesota Vikings at Candlestick Park.

Whether he actually plays is unclear.

"I don't think the 1s are going that much," he said about the first-team offense.

The wide receiver also said that his latest limited offseason will not slow down his development. He pronounced himself pain free — at least for now — and participated in all team drills except the 2-minute offense for the first time this training camp in Tuesday's afternoon practice after doing individual drills the last few days.

"It's always something different in football," Crabtree said. "I'm sure everybody go through stuff. It was just my calf, and I had to stay off of it. I didn't want nothing serious to happen to it. Like I said, it was all the training staff and coaches did that stuff for me. When they say I'm going, I'm going."

This training camp has followed a similar pattern to Crabtree's career.

Crabtree has missed all 12 preseason games the last three seasons because of two foot surgeries, a neck injury and a lengthy contract holdout after San Francisco drafted the Texas Tech wide receiver 10th overall in 2009. He injured his calf on the first day of training camp this year and is still sporting a black sleeve over it.

Crabtree caught 72 passes for 874 yards and four touchdowns last season in San Francisco's tight end-friendly offense. He has 175 receptions for 2,240 yards and 12 touchdowns in his career.

This offseason was supposed to be different.

The 49ers signed free agent receivers Randy Moss, Mario Manningham and drafted A.J. Jenkins 30th overall out of Illinois with the team's only first-round pick. With quarterback Alex Smith coming off a breakout season behind NFL Coach of the Year Jim Harbaugh, the returning staff finally offers some continuity on offense.

Crabtree fired back at reporters when asked about not having another "full offseason schedule." He said every player misses time — "You think everybody goes like every day of camp?" he asked at one point — and said his situation is no different than any other 49ers player, even though Crabtree is the only starter to miss every exhibition the last three years.

"I don't think about it like that," he said. "I think about it like football, and whenever I can go, I'm going. If I can't go or they won't let me go, then I can't be out there. I look at it like as football, man. I'm listening to the training staff and coaches and what's wise for me to do."