Tazawa has appeared in 61 games (58 2-3 innings). He is 2-7 with a 4.14 ERA.
''I just want to make this perfectly clear: There was no injury,'' Boston acting manager Torey Lovullo said Tuesday night after a 6-5, 13-inning loss at Baltimore. ''There was nothing behind this other than us giving him a rest. He feels good. He could pitch if we asked him to.''
Tazawa made more than 70 appearances in each of the past two seasons and was close to reaching that number again this year. Lovullo said the goal is for him to rest and then get ready for 2016.
Lovullo said: ''Taz has been a warrior for the past three years. It was just our way to pay him back. Let's just get a jump start on the offseason.''