Matusz will start Sunday's game against the Mariners, Bruce Levine of 670 The Score reports.

EDGE Analysis

As expected, Matusz will come up from Triple-A to make a spot start Saturday opposite Seattle's Felix Hernandez. The 29-year-old lefty has spent the bulk of the year in the minors, where he holds a cumulative 3.58 ERA across 10 appearances (five starts) at the Rookie, High-A, Double-A and Triple-A levels. In a corresponding move, the Cubs have optioned Justin Grimm to Triple-A Iowa.