Vikings running back Adrian Peterson was limited in today's practice because of back injury suffered in Sunday's game against Detroit. Before anyone gets too excited, Peterson was taking part in practice during the brief period the media was allowed to watch at the start of the session and did not appear to be slowed. That, however, was only stretching and individual drills.

Peterson is no stranger to the injury report and has been limited in practice before, but he also has missed only two games in his two-plus NFL seasons and that was because of a knee injury he suffered as a rookie in Green Bay.

We mentioned in the earlier blog that middle linebacker E.J. Henderson was doing some jogging off to the side and that we weren't aware he was injured Sunday. Turn outs, Henderson has an issue with his shoulder and did not do any work in today's practice. It will be interesting to see what type of progress Henderson makes this week. Wednesday and Thursday are key days of practice in the NFL and if Henderson misses them both there is no guarantee he would play Sunday against San Francisco.

Also joining the injury report is safety Madieu Williams. He was limited because of a shoulder issue on Wednesday. Williams left Sunday's game against Detroit briefly because his braces cut through his lip while he was making a tackle. Not sure if he hurt his shoulder on the same play.

E.J.'s brother, Erin Henderson, was back on the field today to watch practice and do some work to the side but he remains unable to practice because of a calf injury. He was hurt in the preseason finale and was expected to miss about a month.

Tight end Jim Kleinsasser remains listed on the injury report with a hand issue but has not missed any time in the past week-plus. Kleinsasser hurt his hand in the preseason opener at Indianapolis.

We do not have the 49ers injury report yet.

Update: 49ers injury report

San Francisco running back Frank Gore (ankle) was limited in practice. Gore rushed for 207 yards in the 49ers victory over Seattle on Sunday.

Also limited were starting left guard David Baas (ankle) and backup linebacker Marques Harris (toe). Linebacker Ahmad Brooks (knee) and running back Glen Coffee (hip) were able to participate in full. Defensive end Justin Smith, who the Vikings courted in free agency in March 2008, did not practice but it was not injury related.