The 27-year-old joins a 10-man bullpen. Toronto currently has 32 players on its roster and it's possible that number will expand when Buffalo's season comes to an end on Monday, but the Blue Jays aren't expected to make many more additions.
Rowley broke onto the scene on Aug. 12 and picked up a win in his big league debut after allowing just one run over 5 1/3 innings in a start vs. the Pirates. Along the way, he became the first graduate of the United States Military Academy to appear in the Major Leagues.
The native of Georgia began the year with Double-A New Hampshire and was then promoted midway through the year to Buffalo. He posted a 2.24 ERA over 116 1/3 combined innings in the Minors.
Gregor Chisholm has covered the Blue Jays for MLB.com since 2011. Follow him on Twitter @gregorMLB and Facebook, and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.