The clubs announced the trade Friday. The A's will make a 25-man roster move when Doubront reports to Oakland, which is hosting Cleveland this weekend. He will help fill a void in a rotation that lost lefty Scott Kazmir in a trade to his hometown Houston Astros last Thursday.
Doubront has split time between Toronto and Triple-A Buffalo, going 1-1 with a 4.76 ERA in five games with four starts while with Toronto. In nine total starts with Buffalo, he was 1-3 with a 2.44 ERA and struck out 43 batters in 48 innings.
Doubront was the odd man out after the Blue Jays acquired shortstop Troy Tulowitzki this week.