Sawamura returned to Japan on Saturday to sign with the Chiba Lotte Marines, Pete Abraham of The Boston Globe reports.

Sawamura was released by the Red Sox on Sunday, Christopher Smith of The Springfield Republican reports.

The Red Sox outrighted Sawamura to Triple-A Worcester on Wednesday, Chris Cotillo of The Springfield Republican reports.

Sawamura was designated for assignment by the Red Sox on Sunday, Pete Abraham of The Boston Globe reports.

Sawamura was recalled from Triple-A Worcester on Monday.

Sawamura was optioned to Triple-A Worcester on Saturday.

Sawamura (0-1) was credited with Saturday's extra-inning loss without getting an out. He gave up one unearned run on a walk and his own throwing error.

Sawamura threw two-thirds of a scoreless inning in Tuesday's 5-3 win over the Tigers.

Sawamura is dealing with a hamstring issue and may have be be replaced on the ALCS roster, Chris Cotillo of The Springfield Republican reports.