The Cubs designated Peralta for assignment Saturday, Bruce Levine of 670TheScore.com reports.
Peralta was brought in last month via a waiver claim but will now give up his 40-man spot to right-hander Jayden Murray, whom the Cubs acquired in a trade with the Astros. The left-handed Peralta has put up a 4.70 ERA and 1.76 WHIP in 15.1 innings with Triple-A Iowa since joining the organization.