McCaughan will be traveling with the Mariners to San Francisco for the three-game series against the Giants that begins Monday, and he'll presumably serve as a spot starter Wednesday if Bryce Miller (finger) is forced to miss his scheduled turn, Ryan Divish of The Seattle Times reports.
Divish notes McCaughan, who has a 3-4 record, 6.56 ERA and 1.49 WHIP across 14 appearances (13 starts) at Triple-A Tacoma, was in the Mariners clubhouse postgame Sunday ahead of the road trip, although no official announcement of him being on the taxi squad has yet been made. The right-hander has made two appearances at the big-league level this season, pitching to a 6.75 ERA and 2.25 WHIP with a 7:3 K:BB across four innings. Miller's status may come down to how he's feeling Tuesday, with manager Scott Servais previously confirming the right-hander was receiving constant treatment for the painful blister that forced him out of Friday's start against the White Sox early.