Last week, Nill added centers Tyler Seguin, Rich Peverley, and Shawn Horcoff to the club. Because of those prior moves that have created a logjam of sorts at the center position (and the fact that Mueller split time between Nashville and Milwaukee), this appears to be a depth move to help restock the farm system and nothing more.
Last season, Mueller played a total of 73 games (55 with Milwaukee and 18 with the Predators). During his time in Nashville, he registered a pair of goals and 3 assists. His 189 points in 323 career AHL games obviously suggest he's not a big point guy by any stretch of the imagination. But he did have a nice 2011 Calder Cup playoff run with 11 points in 13 games that spring.
Up until today, Mueller had spent his entire pro hockey career in the Nashville Predators' system, having been signed as an undrafted free agent on December 27, 2010.