Medina, 26, was acquired from the Seattle Mariners for catcher Welington Castillo on May 19 and has since appeared in 10 games for Iowa, producing a 2.57 ERA (2 ER/7.0 IP) in his last six relief appearances dating to May 31.
The 6-foot-3, 245-pound righthander has posted a 2.82 ERA (43 ER/137.0 IP) in 141 appearances out of the Mariners bullpen the last three seasons, turning in a 10-9 record with 43 holds and two saves. He has struck out 140 batters in 137.0 innings while limiting opponents to a .216 batting average, including a .228 mark vs. right-handed hitters and a .198 mark vs. lefthanders. Medina has held opponents to a .325 on-base percentage and only a .321 slugging percentage, good for just a .646 opponents OPS.
Medina broke into the big leagues with the Mariners in 2013 and went 4-6 with one save and a 2.91 ERA (22 ER/68.0 IP) in 63 relief appearances while ranking second among all American League rookies with 19 holds. Last season, he improved upon those numbers by going 5-3 with 21 holds and a 2.68 ERA (17 ER/57.0 IP) in 66 relief outings while leading the Mariners and ranking 12th in the league in holds. This year, Medina was 1-0 with three holds, one save and a 3.00 ERA (4 ER/12.0 IP) in 12 relief outings for Seattle prior to the trade.
Medina is a native of Puerto Cabello, Venezuela and originally signed with the Mariners as a non-drafted free agent in 2005.
Rosscup, 27, is 2-1 with a 4.30 ERA (11 ER/23.0 IP) in 26 relief appearances for Chicago this season after he was recalled from Iowa, April 14. He is 3-1 with a 5.44 ERA (26 ER/43.0 IP) and 53 strikeouts in 54 career relief outings for the Cubs spanning parts of the last three seasons.