Beckham had his contract purchased from Triple-A Tacoma on Monday.
Beckham will join the Mariners for the first time all season to offer additional infield depth with Robinson Cano (finger) landing on the disabled list. The veteran infielder compiled a solid .300/.412/.500 slash line to go with four homers across 25 games with the Rainiers this season. Beckham, who owns a career .239/.303/.369 slash line across 964 major-league games, will help man the keystone with Andrew Romine in Cano's absence, though it's unclear how playing time will shake out at this point.