Even though he is a free agent, Alex Smith has been endorsed by coach Jim Harbaugh as the San Francisco 49ers' quarterback. Receiver Michael Crabtree apparently isn't convinced Smith deserves the job.

Crabtree joined 49ers informal workouts for the first time Monday, when offensive players began a four-day "minicamp" at San Jose State. He has missed other informal workouts despite being in the Bay Area.

When asked by reporters if he thought catching passes from Smith was important to building chemistry, Crabtree responded: "Who's the quarterback?"

When told Smith was the likely starter, Crabtree said: "He's the quarterback? I'm just asking."

Crabtree told reporters that whoever starts at quarterback for the 49ers would get his support, but he's still not sure who that player will be.

"I wish I could tell you that," he told reporters. "I know what you're all scratching at. I wish I could tell you who is going to be the quarterback. I don't know. I don't know. Whoever the quarterback is, I'm 100 percent down with it and I'm ready to go. That's it."

Last week, Smith seemed to take a shot at Crabtree in an interview with the San Jose Mercury News when he was asked about Crabtree's absence from workouts.

"Great question," Smith told the newspaper. "Asking the wrong guy, honestly."

Crabtree told the San Francisco Chronicle he was doing the same things his teammates were doing, just in another setting and with college players.

"Routes, every day," Crabtree told the Chronicle. "I do just what they have been doing here. At a park. Nice field. It's in the mountains, too."

During the brief period when the lockout was lifted this offseason, Smith left team headquarters with a playbook -- not a common practice for an unsigned player considering how teams so closely guard their schemes -- though these are unique circumstances with the NFL in lockout limbo. The 49ers had to be pretty confident in their chances of bringing him back to hand over Harbaugh's playbook.