Borucki was optioned to Triple-A Buffalo on Saturday, Gregor Chisholm of MLB.com reports.
This was a procedural move; the Blue Jays won't need a fifth starter until July 24. They decided to bring up some extra relief help in the meantime. Borucki is expected to return for that July 24 start against Minnesota. He's allowed nine earned runs while posting a 21:10 K:BB in 23 innings with the major-league team so far.