Armstrong didn't factor into the decision in Tuesday's 7-2 win over the Marlins, allowing three hits over three scoreless innings. He struck out one without walking a batter.
Pressed into duty as a spot starter after Shane McClanahan (shoulder) was a late scratch, Armstrong fired 36 of 48 pitches for strikes in an impressive performance. The Rays will look for a more permanent replacement in the rotation for McClanahan, so Armstrong should return to the bullpen, but the right-hander has worked more than one inning in six of his last nine appearances and would likely be a key part of any future bullpen days for Tampa. In 33 games since joining the Rays, he sports a 3.73 ERA, 1.32 WHIP and 47:9 K:BB through 41 innings.