The Red Sox optioned Seigler to Triple-A Worcester on Sunday.
Seigler will give up his spot on the active roster to Trevor Story (sports hernia), who was reinstated from the 60-day injured list. Over 171 plate appearances in the big leagues this season, Seigler has slashed .250/.331/.405 with three home runs, two steals, 21 runs and 13 RBI.