49ers' injury wire

SANTA CLARA, Calif. -- As expected, standout guard Mike Iupati practiced Wednesday for the first time since he sprained his knee at New Orleans on Nov. 17.

Barring a setback, heis now on track to play after missing three games.

Meanwhile, cornerback Tarell Brown was cleared for contact Wednesday after practicing in a non-contact jersey. He hasn’t played since the Saints’ game as well when he injured his ribs. Still, Brown will likely back up Tramaine Brock, who took over for him. Brock has been outstanding.

Receiver Michael Crabtree was limited Wednesday with an ankle injury he suffered Sunday. The fact that he practiced some, after suffering an injury so soon after his return from a torn Achilles, is a good sign.

Left tackle Joe Staley practiced fully Wednesday. That is a sign he came out of Sunday’s win over Seattle in good shape. He sprained his knee Dec. 1 against the Rams and missed most of that game.

Adam Snyder, who has played in Iupati’s place, didn’t practice for non-injury reasons.

Meanwhile, in other 49ers’ injury-related news, coach Jim Harbaugh said Wednesday the reason why rookie defensive lineman Tank Carradine was put on the injured reserve this week was was not because he had a setup. Carradine, a second-round pick, tore his ACL at Florida State in 2012. He was activated by the 49ers last month but he never played a down in the NFL.

“There was no setback,” Harbaugh said.” Actually there’s been steady progress. Just feel like in his best interest, playing games, he’d be better suited off to have another good offseason. But, it’s not that he couldn’t play this year, but just don’t feel that he’s 100 percent ready or able to play in games. His rehab has been steadily improving. Just in his best interest to hold him until next year.”