The move means Milwaukee has seven days to either trade McCullers Jr. or place him on waivers. In the latter situation, McCullers Jr. could either be picked up by another club or get passed by; and in that case, the Brewers could attempt to place the two-time world champion in the minor leagues, though he would have the ability to reject the assignment thanks to his major league service time.

But essentially it means McCullers Jr., 32, is likely to not resurface on the Brewers' big league club. He was acquired by Milwaukee on July 15 along with pitcher Colton Gordon for third-generation prospect Jadyn Fielder. McCullers had to waive his no-trade clause for the trade to occur.

After arriving in Milwaukee, McCullers Jr. had just two outings. He allowed two earned runs with four strikeouts and a walk in three innings in a 8-3 win on July 20 against the Mets. Then on Saturday, McCullers Jr. entered a game against the Colorado Rockies in the eighth inning with a 7-2 lead. He generated two outs before allowing two walks, then recorded the third out. In the ninth inning, McCullers Jr. walked the leadoff batter before getting in some trouble, thanks in part to poor Milwaukee defense. He left after giving up four walks, a hit and two runs, both unearned.

The Brewers already have a packed bullpen led by closer Trevor Megill. After designating McCullers Jr. on Sunday, Milwaukee recalled right-handed pitcher Garrett Stallings from triple-A Nashville. Stallings has three innings of unearned ball under his belt with the Brewers this season.