Starting safeties Donte Whitner and Eric Reid were on hand for the start of practice, and both are expected to play Sunday against the Jaguars. "I think they're going to be fine," Jim Harbaugh said.
Whitner injured his left knee late in Sunday's win over the Titans while Reid rolled an ankle. Neither was on the field for Chris Johnson's 66-yard yard catch-and-run touchdown in the fourth quarter.
Wednesday's practice began without starting defensive linemen Justin Smith, Ray McDonald and Glenn Dorsey. Smith is dealing with a shoulder injury, and he may get Wednesdays off for the rest of the season because of his veteran status. McDonald (biceps) and Dorsey (hamstring) are recovering from injuries. All three of the linemen are expected to play Sunday.
Receiver Mario Manningham, who is recovering from a December ACL tear, also was at practice and looked to be in good shape. Harbaugh said there was a possibility one of three players currently on injury lists - Manningham, cornerback Eric Wright and defensive end Tank Carradine - could be elevated to the active roster as defensive lineman Quinton Dial was last week.
Such a move would require the 49ers to create a roster spot. If Manningham were elevated, one possibility would be to release receiver Marlon Moore, who has been inactive twice this season, or to put rookie Quinton Patton on injured reserve. Patton suffered a broken foot in Week 4.
When the 49ers were in London three years ago, they released safety Chris Maragos, who had been on the 53-man squad at the time. Later that week, they added him to the practice squad, and he never had to leave the team.
-- Matt Barrows