The Cubs designated Cuas for assignment Sunday, Tim Stebbins of MLB.com reports.
Cuas will now be placed on waivers, and if he goes unclaimed, he'll likely remain in the organization as a reliever at Triple-A Iowa. The right-hander has struggled to a 6.35 ERA over 11.1 innings in 10 appearances in the minors and will have to right the ship before earning another shot on the 40-man roster.