ATLANTA -- Right-hander Adbert Alzolay, who opened the season as the Chicago Cubs' closer, was placed on the 15-day injured list on Monday with a right forearm strain.
Right-hander José Cuas was recalled from Triple-A Iowa. On Tuesday, the Cubs announced the acquisition of right-hander Tyson Miller from the Seattle Mariners in exchange for minor league infielder Jake Slaughter.
Alzolay is 1-4 with a 4.67 ERA and has four saves in nine opportunities. Héctor Neris, who has six saves in seven chances, has moved into the closer's role though Alzolay earned the save in the Cubs' 5-4 win in 10 innings at Pittsburgh on Sunday. Neris was the winning pitcher.
Alzolay becomes the eighth current Cubs player on the injured list.
Cuas was recalled from the minors on Saturday when Yency Almonte was placed on the IL with a right shoulder strain. Cuas was then sent back to Iowa one day later when Kyle Hendricks was activated from the injured list.
Miller, 28, made nine relief appearances for the Mariners this season. He had a 3.09 ERA , 12 strikeouts and just one walk. He was originally drafted by the Cubs as a fourth-round pick in 2016.
Slaughter, 27, has appeared in 32 games this season for Triple-A Iowa, hitting .297 with five home runs and 17 RBI.
Left-hander Richard Lovelady was designated for assignment by the Cubs to clear a spot on the 40-man roster. Lovelady was 0-1 with a 7.94 ERA with Chicago.
Information from The Associated Press was used in this story.