As Grant pointed out, Matt Harrison has never in his entire career been much of a strikeout pitcher. He's struck out six or seven batters per nine innings in his career, and he's never struck out more than nine batters in one game in his whole major-league career. He's just not a strikeout pitcher, even though he routinely throws low- and mid-90s fastballs.
Until today. Today he's a strikeout pitcher, matching his career high with nine K's in the first four innings of Game 4, with a berth in the League Championship Series at stake. But Harrison hasn't been untouchable, giving up two runs in those four innings. Harrison didn't add to his strikeout total in the fifth, but he didn't add to his run total, either.
But with all those strikeouts (and two walks), Harrison's already thrown 97 pitches, and figures to pitch, at most, one more inning. Meanwhile, rookie Matt Moore, Tampa Bay's Game 1 winner, took the hill in the top of the fifth and is again mowing down Rangers with (apparent) ease.
Score through 5½ innings: Rangers 3, Rays 2