He stretched his scoreless streak to 17 innings Tuesday but left a 3-0 win over the New York Mets after hyperextending his right knee while lunging for Chris Young's flare between the mound and first base.
Wainwright said Thursday his knee was "a hair sore — on fully extension only."
"And when you look at the way I pitch, you barely do anything stiff-legged, so I'm going to be OK," he said.
Wainwright is 4-1 with a 1.46 ERA.