SANTA CLARA -- Wide receiver Michael Crabtree missed his first practice of training camp Thursday, and it's unknown whether his past Achilles or foot injuries are the reason.
"Mike's just working though something. He's fine," said offensive coordinator Greg Roman, who proceeded to praise how improved Crabtree is from his injury-shortened 2013 season.
Crabtree was seen Wednesday off to the side testing out his lower right leg while practice finished up without him.
Crabtree has impressed through the first week of camp. Colin Kaepernick said Tuesday that Crabtree looked a step or two quicker and 100 percent recovered from last year's right Achilles tear that sidelined him the first 11 games.
Most of Thursday's session focused on special teams but there was also two-minute drills and red-zone work.
Also sitting out were wideout Brandon Lloyd, tailback LaMichael James, cornerback Tramaine Brock, right tackle Anthony Davis and defensive linemen Justin Smith, Ray McDonald and Demarcus Dobbs.
The 49ers were cautious with Crabtree through the offseason program, as he typically worked on the side during team drills.