Guaipe was optioned to Triple-A Tacoma on Wednesday, Bob Dutton of the Tacoma News Tribune reports.
After acquiring Nick Vincent in a trade with the Padres, the Mariners were expected to send Guaipe to the minors, but this seals the deal. He pitched well this spring, posting a 2.45 ERA and 0.73 WHIP in 11 innings pitched, but there simply wasn't room for the right-hander in the Seattle bullpen. He could get a callup to the big leagues if he continues to have success in the minor leagues, though.