Alzolay, 24, joins the Cubs currently ranked as the No. 4 prospect in the organization by MLB.com. He has gone 2-1 with a 0.94 WHIP and 3.09 ERA (11 ER/32.0 IP) in six starts with Iowa this season, recording 46 strikeouts with only six walks in 32.0 innings pitched while limiting foes to a .203 batting average. Alzolay has been especially dominant in his last five starts, turning in a 1.93 ERA (6 ER/28.0 IP) with only three walks and 40 strikeouts in 28.0 innings. He earned Pacific Coast League Pitcher of the Week honors for the period ending June 2.

The righthander was originally signed by the Cubs at the age of 17 as a non-drafted free agent in 2012 and enjoyed his first full minor league season in 2016 when he earned Midwest League All-Star honors with Single-A South Bend, going 9-4 with a 4.34 ERA (58 ER/120.1 IP) in 22 appearances (20 starts). In 2017, Adzolay was an All-Star for Single-A Myrtle Beach when he went 7-1 with a 2.98 ERA (27 ER/81.2 IP) in 15 starts to earn his first promotion to Double-A Tennessee.

Alzolay began the 2018 campaign ranked by MLB.com as the top pitching prospect in the Cubs organization but saw his season cut short after only eight starts due to a lat strain endured on May 29. Alzolay went 2-4 with a 4.76 ERA (21 ER/39.2 IP) in those eight starts with Iowa, his first stop at the Triple-A level. He began the 2019 campaign at extended spring training and made one start with Myrtle Beach on May 12 before making his first start with Iowa on May 17.

A native of Puerto Ordaz, Venezuela, Alzolay has gone 33-24 with a 1.13 WHIP and 3.48 ERA (177 ER/457.2 IP) in 96 appearances, 75 as a starter, covering the last seven seasons in the Cubs minor league system.

Collins, 29, posted no record and a 3.52 ERA (3 ER/7.2 IP) in eight relief outings with the Cubs this season. With Iowa, he went 1-1 with a 2.12 ERA (4 ER/17.0 IP) in 17 relief appearances.

Chicago’s 40-man roster now stands at 39 players.