BOSTON -- Red Sox starter Clay Buchholz said Wednesday he has been feeling some "fatigue" in his throwing shoulder and that he won't start until Game 4 of the World Series on Sunday in St. Louis.

Clay Buchholz will start for the Red Sox in Game 4 Sunday night. Al Bello/Getty Images

"Everything that he's going through right now is indicating that he will start on Sunday," Red Sox manager John Farrell said prior to Game 2 on Thursday. "There's been nothing that has happened since we spoke [Wednesday] here or with Clay that would indicate otherwise. So we fully expect him to go."

Buchholz missed three months of the regular season with neck and shoulder issues before returning to make four starts in September and three postseason starts. His velocity has diminished and he has worn down late in each of those starts, giving up a combined 12 runs and 25 hits in 21 2/3 innings. He has thrown fewer than 90 pitches in each of his past two outings.

Buchholz said he has undergone strength tests and has complained about a constant tightness.

"It's just a little dead at certain points," he said after Wednesday's 8-1 Red Sox victory in Game 1. "It's not like a pinpoint straight spot where I can say, 'Yeah, there it is.' It's just general."

He went on to describe it as "just a feeling you don't like feeling going into the World Series. It's not out of the ordinary, at the same time this is when you want to be at your best and that's what I'm trying to get back to."

Jake Peavy will go in Game 3, leaving Buchholz with just one remaining start the rest of the way. Peavy would be lined up to pitch a potential Game 7, as well.