Peterson did not factor into the decision in Saturday's 5-2 win against the Yankees, allowing two runs (one earned) on five hits and no walks with eight strikeouts over 6.1 innings.
Thielbar earned the save in Saturday's 5-2 win over the Yankees, allowing one hit in a scoreless ninth inning. He did not record a walk or a strikeout.
Imanaga (7-9) was saddled with the loss Friday as the Cubs fell 2-0 to the Yankees, allowing two runs on four hits over 6.2 innings. He struck out six without walking a batter.
Assad did not factor into the decision for Thursday's game against the Cardinals, allowing one run on six hits and two walks while striking out six across 4.1 innings.
Webb (4-2) worked around a hit to toss 1.1 scoreless innings and earn the win in Thursday's 4-2, 10-inning victory over the Cardinals. He had no strikeouts or walks.
Thornton (3-4) allowed three runs (two earned) on two hits and a walk while retiring only one batter to blow the save and take the loss Wednesday against the Cardinals.
Imanaga is no longer listed as the Cubs' starting pitcher for Thursday's game in St. Louis and will instead take the hill Friday versus the Yankees at Wrigley Field, Meghan Montemurro of the Chicago Tribune reports.