MacGregor made his debut for Altoona on May 5, a date that marked his first appearance in affiliated ball since August 2018. The right-handed missed the entire 2019 season while recovering from Tommy John surgery, then didn't pitch in 2020 due to the cancellation of the minor-league season. The 23-year-old appears to be healthy after the long layoff, and while the organization is expected to be conservative with his usage in 2021, it's not out of the question for him to get a call-up to the big leagues before the end of the season if he continues to make bats miss at a prolific rate.

A 6-foot-3, 180-pound projectable righty, MacGregor wasn't really on the dynasty-league radar, but he could have gotten himself there with a healthy, productive season at High-A. Instead, he will be on the shelf all season and may not even be healthy in time to pitch in winter ball. He will likely head back to Low-A to open the 2020 season to knock off rust before an assignment to High-A.