Center John Sullivan remains sidelined, but there was a positive development regarding another injured Vikings player today.

Second-year nose tackle Shamar Stephen, who had his left knee scoped three weeks ago, returned to practice for the first time in more than a month. Stephen participated in individual drills with his fellow defensive linemen in the portion of practice opened to media. They booted us before team drills.

Stephen started training camp on the non-football injury list with his knee injury. After Stephen returned to practice and played in the preseason opener, the Vikings shut him down for the rest of the preseason.

Stephen is one of four defensive tackles on the roster, though second-year end Scott Crichton might be able to play in a pinch.

Meanwhile, regarding Sullivan, coach Mike Zimmer said yesterday that he isn't concerned about Sullivan and that the center would try to practice today. Alas, Sullivan missed his 12th straight practice and was last spotted on the practice field exactly three weeks from today.

Fullback Zach Line did not participate in practice for a second straight day. He instead did conditioning work on the side with practice-squad linebacker Brian Peters, who was also held out of all drills today.