Thielbar (oblique) has resumed playing catch and is expected to throw off the mound next week, Betsy Helfand of the St. Paul Pioneer Press reports.
Thielbar is currently on the injured list with a right oblique strain, but the strain is considered "moderate" and it's a positive development he's back to throwing. It seems likely Thielbar will need a rehab assignment, but he could be back as an option for the Minnesota bullpen around the start of June.