Head coach Kyle Shanahan was asked on Monday why Smith was limited against the Buccaneers. Apparently, Smith is dealing with an injury that he tried to play through.
"It's the same thing he's been dealing with," Shanahan responded. "He has tendinitis in his lower leg. (He) came back from the bye week, it was bothering him all week. He tried to go for most of the first half, and then Elijah (Lee) took over in the second."
Elijah Lee ended up playing 49 snaps in the game, his second-largest total in a single game this season (72 in Week 2).
Shanahan went on to say the 49ers will likely have to add a linebacker and safety sometime this week. In addition to Smith ailing, safety Jimmie Ward left Sunday's game with a broken forearm and will be lost for the remainder of the season.