ST. LOUIS -- There was no hedging, no equivocating. Red Sox manager John Farrell said Friday that Clay Buchholz will be starting Game 4 of the World Series Sunday night against the Cardinals.

After his formal media session Friday, Farrell disputed speculation that Buchholz cut short his throwing before Game 2 Thursday because of shoulder discomfort. Buchholz played only a short game of catch before stopping.

"No, no, no," Farrell said when asked if Buchholz had been unable to continue. "There are gradual steps he was building up. Today was much more intense, much greater volume. He's working in lockstep with our medical staff on this."

In his media session, Farrell said: "He went through his throwing program today. Got out to about 100 feet with increased intensity along the way. He's starting Sunday."

Red Sox pitcher Jake Peavy, who is starting in Game 3 and also appeared before the media, likened Buchholz's situation to that of Cardinals outfielder Carlos Beltran, who played Game 2 despite sustaining bruised ribs while robbing David Ortiz of a grand slam in Game 1.

"I'm really not that concerned, to be honest with you," Peavy said. "We're at the finish line now. I certainly hate that he's experiencing any kind of discomfort, and we all know that he missed some significant time with a shoulder injury, but I think Clay is on that same bandwagon, and we started this press conference talking about Carlos Beltran.

"I can't imagine what it would take for somebody who's been hurt, who's been injured. I think you could just physically have to not be able to play the game of baseball to not go out there and compete in this environment, when the adrenaline and the atmosphere can help you through a lot of that, as well as maybe some drugs."

Buchholz has a 5.91 ERA and no win-loss record in two postseason starts. He gave up a 3-0 lead in Game 3 of the American League Division Series against Tampa Bay -- when Evan Longoria hit a three-run home run in the fifth -- and departed with the score tied 3-3 after six in a game the Rays won 5-4 on Jose Lobaton's walk-off home run off Sox closer Koji Uehara.

He pitched the deciding Game 6 of the ALCS, but left after allowing the first two batters of the sixth inning to reach safely on a walk and single. His velocity had dipped to 88 miles per hour in the inning, and he was lifted despite having thrown only 85 pitches. Both of those runners came around to score, and Buchholz was the pitcher of record until Shane Victorino's grand slam gave the Sox a 5-2 win and a trip to the World Series.

Buchholz acknowledged feeling some shoulder tightness and fatigue after Game 1. The Red Sox held off on announcing their Game 3 starter until after Game 1, when Farrell announced that Peavy, who had been the fourth man in the rotation through the first two rounds, would pitch Game 3 and Buchholz Game 4. That would leave Peavy in line to start Game 7 on regular rest, if necessary.

Buchholz said Wednesday he had undergone strength tests after complaining of tightness.

"It's just a little dead at certain points," he said. "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."

Buchholz, who last pitched Oct. 19, said the fatigue he is currently feeling is different than the discomfort that shelved him for most of the season. He also said he's not concerned.

"It's nothing like what I had to take that long break during the season," Buchholz said. "It's nothing to that extent. When I got hurt during the season, I threw a pitch and said, 'OK, I don't think I can throw another one.' I started feeling like this in the second inning the other night and ended up going into the sixth.

"My outlook on it is for me to take a couple of days of treatment and rest, pumping in the fluids and keeping the anti-inflammatories in my system. I'll be ready to pitch on Sunday."