Clay Buchholz was looking to extend his record to 8-0 on Monday night before making the decision not to play because of irritation in his right AC joint.

The right-hander, who is off to a 7-0 start on the season, will sit out Monday night’s matchup that starts a two-game home-and-home series with the Phillies. Buchholz told reporters he woke up the day after the Red Sox returned from Chicago and felt something off in his right AC joint.

Manager John Farrell said there is no cause for concern, and Buchholz agreed, telling reporters it was mostly a precautionary measure because it’s so early in the season. Alfredo Aceves will instead get the start.

Buchholz boasts a 1.73 ERA with 73 strikeouts this season.

Check out the video above to hear what Buchholz had to say about missing the start, or check it out on NESN’s YouTube channel.