Arias will be promoted to Triple-A Worcester, Tommy Cassell of the Worcester Telegram & Gazette reports.
Arias will make the jump to the Triple-A level after batting .318 with 19 home runs, 52 RBI, 50 runs scored and five stolen bases over 75 contests with Double-A Portland this season. The 20-year-old is considered Boston's top overall prospect, and he is now just one step away from making his major-league debut.