Buelvas was promoted from High-A Lansing to Double-A Midland on Tuesday, Melissa Lockard of The Athletic reports.
The 21-year-old outfielder couldn't get his bat going in the Midwest League this year (.135/.211/.243 slash line), but he put up a 140 wRC+ for Single-A Stockton earlier this season. Buelvas is a plus runner, but his struggles as an age-appropriate prospect at High-A are a bit concerning.