The Mariners promoted Montes from Double-A Arkansas to Triple-A Tacoma on Sunday, Daniel Kramer of MLB.com reports.
Montes slashed .234/.369/.550 with 25 home runs at Arkansas, which included a 1.199 OPS in June. Contact remains an issue, as the hulking slugger has struck out at a 30.4 percent clip in 2026, but he has some of the best power of any minor-league hitter and has a chance to reach the majors before the end of this season.