Johnson (elbow) was added to the Orioles' 40-man roster Tuesday.
It's a testament to Johnson's stuff that the Orioles not only traded for him at the deadline in the three-team trade that sent Trey Mancini to Houston and Jose Siri to Tampa Bay while knowing he needed Tommy John surgery, but they will protect him from the Rule 5 draft while he recovers despite the fact he has never pitched above High-A. Given the timing of the surgery and Johnson's lack upper-level work, it will be a small margin of error for him to make it as a big-league starter, but he could be a devastating reliever if his stuff returns to pre-injury form.