Kirby is considered a candidate for the Mariners' vacant No. 5 starter role, Daniel Kramer of MLB.com reports.
The Mariners' No. 3 prospect logged 67.2 innings last season between High-A Everett and Double-A Arkansas, putting together a 5-3 record, 2.53 ERA and 1.08 WHIP while generating an 80:15 K:BB. The fact Kirby worked the fewest frames between him and fellow candidates Matt Brash and Levi Stoudt a year ago may hurt his chances to a degree, however, as Kramer notes Seattle intends for him to pitch deep into the season and would therefore likely have to keep a closer eye on his workload.