Rainer was promoted to High-A West Michigan on Monday.
The timing of the promotion is a bit surprising, as Rainer is slashing only .167/.265/.310 with a 40.8 percent strikeout rate at Single-A Lakeland. Rainer -- who missed the final few months of the 2025 season following surgery to repair a dislocated right shoulder -- will try to get on track as he reaches the Midwest League.