The acquired right-hander from the on Saturday in exchange for cash considerations.
The Reds optioned Van Belle to Triple-A Louisville. The Red Sox had designated him for assignment on Wednesday.
Van Belle, 28, has yet to make his major league debut. He was 5-1 with a 2.29 ERA in 12 games (eight starts) this season at Triple-A Worcester.
Since breaking into Boston’s system in 2021 out of Miami (Florida), Van Belle is 37-19 with a 4.41 ERA in 115 games (84 starts) in the minor leagues. He has struck out 479 batters and walked 120 in 502 1/3 innings.
