Clay Buchholz is banking that his right shoulder won’t be a problem on Sunday. “It’s going to be my first World Series experience being on the field,” said the Red Sox right-hander, who will be opposed by Lance Lynn in Game 4, with Boston trailing St. Louis two games to one after the Cardinals’ 5-4 win in Game 3 Saturday night. “Just the environment, the crowd, the adrenaline, that’s going to help me out, too.” Buchholz had tightness in the shoulder in his start against the Tigers in Game 6 of the ALCS and was removed after 85 pitches. As a result, Red Sox manager John Farrell switched up his World Series rotation, giving Jake Peavy the start in Game 3 instead of Buchholz. Peavy would be in position to start a potential Game 7. “We go into [Sunday] thinking that he’s going to give us what he’s been in the postseason,” Farrell said. “That might be a little bit shorter of an outing than maybe we’ve seen back in April and May. But he’s also been very effective.” The right-hander has posted a 5.40 ERA in three starts this postseason.