Boston optioned Olds to Triple-A Worcester on Sunday.
Olds spent just under three weeks with the big-league club before being demoted Sunday. Through 13 games, the 26-year-old has posted a 1.20 ERA, 1.20 WHIP and 20:7 K:BB over 15 innings. Boston reinstated Tyron Guerrero (shoulder) from the 15-day IL in a corresponding move.