"I think we feel pretty good about starting him," Melvin said. "We have not made that decision yet. I am going to talk to him today, but I think based on what I'm hearing and how he came through his bullpen session, I think we're in a good spot to start him."
Cahill, who has missed one start because of an impingement in his right elbow, is 1-1 with a 2.25 ERA across four starts since joining the A's rotation.
He is 1-2 with a 6.35 ERA in five career starts against the Red Sox, including 0-2 with an 8.44 ERA in four outings in Boston.
Right-hander Kendall Graveman, who allowed four runs (one earned) in six innings at Yankee Stadium on Friday after being recalled from Triple-A Nashville, was originally scheduled to go Wednesday.
Jane Lee has covered the A's for MLB.com since 2010.