49ers WR Michael Crabtree was limited in practices this week with a bum ankle.

OK, take a guess which team is the worst in the NFL in passing yards? No, not the Bucs (but close, the Bucs are No. 31). It’s the mighty 49ers who have thrown for a league-worst 2,318 yards through 13 games.

This has led some to believe that 49ers quarterback Colin Kaepernick is wildly overrated. Maybe. In his first full season as the 49ers quarterback (remember, he took over for Alex Smith in the middle of the season last year), Kaepernick may have taken a step back because his favorite receiver, Michael Crabtree, was lost to an injury for most of the year.

Crabtree had an Achilles injury and only recently returned. His former teammate and current Bucs safety, “The Hawk,” Dashon Goldson, hinted missing Crabtree played a part in Kaepernick’s decline.

“I wouldn’t say [the 49ers offense] changed [without Crabtree] but him coming off an injury and not being out there with the guys, ‘Kap would develop a little more different if he wasn’t missing,” Goldson said. “But I think they will be back on the same page — this is his second or third week back, right? So I think when he is back healthy and in shape, they will be back to where they were before.”

It’s not just an Achilles injury Crabtree is trying to overcome. He also has a bum ankle and was limited in 49ers’ practices the past two days.

Crabtree is hobbled enough that it is evident to Darrelle Revis that Crabtree, on tape, doesn’t seem to be playing at 100 percent.

“He doesn’t,” Revis said. “Sometimes you can kind of see him favoring that Achilles and I don’t even know which Achilles it is, but you can kind of see him hobbling around out there, here and there on plays. But he’s out there, so there’s no excuse.”

Bucs commander Greg Schiano referred to the 49ers’ receiving corps with Crabtree back, along with Anquan Boldin and Vernon Davis, as a “Pro Bowl receiving corps.”

The Bucs secondary has played well enough recently where Joe isn’t losing sleep, no matter who they face. But if Crabtree can’t go, or is far less than 100 percent, it will certainly be a load off of the shoulders of the Bucs defense.