Eduardo Rodriguez had been scheduled to start Game 4.
But Sunday's rainout allows the Red Sox to bring back Porcello, a 22-game winner, on the usual four days of rest.
"So for me, I can't wait to get back out there and throw the ball the way I'm capable of." "If we get there tomorrow, Rick is the starter.
He's been extremely successful here in Fenway Park, and hasn't gone the 10-12 days in between starts as Eddie has," Farrell said.
"That's the plan tomorrow, provided we get there."