Here's a nice little blurb I found while looking for something else.
"Like Bulluck, Sirmon has been a mainstay for the Titans over the past six seasons. Yet, last season Sirmon’s production was down, as he was still recovering from the ACL injury that kept him out of the entire 2004 schedule. Prior to sustaining the injury in the ’04 training camp, Sirmon had been an extremely reliable linebacker during the 2002 and 2003 seasons.
Sirmon amassed impressive totals last season, but his 89 tackles was a significant dip from the statistics he recorded during the previous two seasons. However, head coach Jeff Fisher expects that with Bulluck and Thornton now surrounding him, Sirmon can become an even better player than he was prior to his injury.
“This off-season has really helped him [Sirmon],” Fisher said. “Last year he focused on just rehabbing the knee. Now he can dwell on the quickness and change of direction. He’s doing much better.”
An outside linebacker throughout his career, Sirmon’s shift to middle linebacker this season will accommodate Thornton’s impressive speed along the sideline. Fisher is confident that Sirmon will adapt well to play in the middle of the field.
“He [Sirmon] doesn’t have any problem with that [switching to middle line backer],” Fisher said, “He knows the defense better than most of the defensive staff.”"
http://www.titansonline.com/news/newsmain_detail.php?PRKey=3867
Though I don't know nuthin about Patriots linebacker choices, this looks intriguing to me. Versatility, smarts........