Mekkes was reassigned to minor-league camp Thursday, Bruce Levine of 670TheScore.com reports.
Mekkes spent all of last year with Triple-A Iowa, where he posted a subpar 5.29 ERA across 49.1 relief innings. He posted a much stronger 1.44 ERA in 31.1 innings at Triple-A in 2018, and he'll look to bounce back this year as he serves as organizational depth for the Cubs.