Whether it's physical, mental or both, some pitchers are having trouble dealing with MLB's crackdown on foreign substances. Garrett Richards is one such pitcher. 

Richards is 0-3 with a 6.75 ERA during his last seven starts. He is 2-3 lifetime when pitching at Oakland with a 4.35 ERA during a span of 51 2/3 innings. 

The A's are tough at home and rate a pitching edge with Cole Irvin, who is coming off an unbeaten June and just beat the Giants this past Sunday. Irvin hurled eight shutout innings against the Giants while giving up just three hits and two walks with eight strikeouts. 

Oakland has won seven of its last 10 home games. The Red Sox are hot, but still have lost four of their last seven road games.