I read in SportingNews that AJ Burnette is testing a changeup.
"AJ Burnette is dabbling with a changeup. He threw five in a spring training start, which he jokingly says was more than he threw all of last season. If Burnette gains confidence in the pitch, it will give him another option to go with his fastball and curve." -March 19 Issue
Verlander said he has been working on a traditional curveball this spring after having to abandon his knuckle-curve during the middle of last season because it was causing blisters, the Detroit Free Press reports.