The 27-year-old was hitting .278 with two homers, 29 RBIs and had a .412 on-base percentage at the time of his suspension. He spent each of the past two seasons in New Hampshire but didn't appear to have much of a future with the organization.
Van Kirk was originally taken in the 21st round of the 2008 First-Year Player Draft. He becomes the second Blue Jays' Minor Leaguer to test positive for a banned substance in the past two years after right-hander Marcus Stroman violated the drug policy in 2012.
Gregor Chisholm is a reporter for MLB.com. Read his blog, North of the Border, and follow him on Twitter @gregorMLB. Paul Casella is a reporter for MLB.com. Follow him on Twitter @paul_casella. This story was not subject to the approval of Major League Baseball or its clubs.