The Chicago Cubs have designated right-handed releiver Luis Vizcaino for assignment, replacing him on the 25-man roster with Jeff Samardzija.
Vizcaino, who the Cubs obtained this past winter from Colorado for righty Jason Marquis, made four relief appearances for Chicago this season and did not allow a run in 3 2/3 innings of work.
The 24-year-old Samardzija, meanwhile, posted no record and a 3.75 ERA (5 ER/12.0 IP) in three appearances (two starts) with Iowa this season. The right-hander limited opponents to a .154 batting average (6-for-39), including a .129 mark by right-handed hitters (4-for-31), and struck out 11 batters in 12.0 innings. Samardzija spent all of spring training with the major league club before being optioned to Triple-A on April 5.
Samardzija made his major league debut with the Cubs last season and turned in a 1-0 record with one save and a 2.28 ERA (7 ER/27 2/3 IP) in 26 relief appearances.