Turnbull was added to the Tigers' 40-man roster on Monday to protect him from the Rule 5 draft, Lynn Henning of the Detroit News reports.
The 25-year-old righty reached Double-A for the first time in his career last season, logging four starts while giving up 14 runs in just 20.1 innings. He should return to Double-A, but now that he is on the 40-man roster, the Tigers may fast-track him to the big leagues to see what they have. It is unclear if he will be a starter or reliever long term, but he is unlikely to be a fantasy asset in either role.