Haase (abdomen) caught a bullpen session and took batting practice Thursday, Cody Stavenhagen of The Athletic reports.
Haase hit the injured list with an abdominal strain earlier in the day, but it doesn't look as though the Tigers are overly concerned about the issue. The team hasn't officially said that he'll be back after a minimum-length stay on the shelf, but the fact that he's already going through baseball activities the same day he hit the injured list seems to hint in that direction.