Mata (lat/elbow) will begin a minor-league rehab assignment with Triple-A Worcester on Tuesday.
Mata has been on the injured list all season, initially due to a hamstring injury before he experienced shoulder and lat soreness in May during his initial rehab assignment. He resumed his rehab assignment in June, only to suffer another setback when he experienced inflammation in his elbow. After resuming his throwing program and completing a bullpen session at Fenway Park on Monday, Mata is ready to restart his rehab assignment for a third time. He'll likely require multiple appearances in the minors before making his return from the 60-day injured list and potentially making his MLB debut in late September.