Clay Buchholz left in the seventh inning of Saturday’s night game against the Angels with what he and manager John Farrell described as “neck tightness.” Buchholz said he first felt the tightness when he threw awkwardly to first base in the sixth inning. On that play, a line drive off the bat of Howie Kendrick struck Buchholz in the hand, knocking his glove off. Buchholz said his hand hurt after the play but wasn’t injured. The problem came when he threw awkwardly to first and felt something off in his neck. “It was just a little nagging there for a couple innings, and then right after that ball that hit off my glove, I threw it to first base and that’s when it sort of tightened up a little bit,” Buchholz said. “And then we get that double play ball and didn’t turn it, and I figured that was enough, didn’t want to push my luck any more with that.” Buchholz remained in the game for the rest of the inning and into the seventh, until, on a grounder Erick Aybar hit to second, the Sox were unable to turn the aforementioned double play, and Craig Breslow came on to get the last out of the inning. The second game of Saturday’s day-night doubleheader, which the Sox won 7-2, was only Buchholz’s second start since missing time with an injury to his AC joint in his shoulder. Farrell said the Sox don’t believe at this point that the two injuries are related. “He stiffened up on the right side of the neck from the [earlier] play at first base, as well as the line drive back up the middle where he had a quick reaction, so it was almost a combination of a couple things that led to the stiffness there,” Farrell said. “We don’t feel at this point that it’s in any way related to the AC irritation that he was feeling previously. He’ll go through a full exam here tonight and, I’m sure, once he arrives at the ballpark tomorrow.” Buchholz said the only connection between the two ailments might be the fact that his shoulder has been a little sore after the work his doctors have done on it since the AC injury.