Toronto optioned Estrada to Triple-A Buffalo on Sunday.
Estrada was excellent in a bulk-relief outing Saturday, holding the White Sox hitless over four innings while striking out three batters and walking two. However, he threw 66 pitches and would presumably be sidelined for several days as a result, so the Blue Jays opted to shuffle him down to Buffalo in order to beef up the team's bullpen. Given Estrada's performance Saturday, it seems very likely he'll be back with the major-league club relatively soon.