Mack (neck) is starting at catcher and batting cleanup in Tuesday's Grapefruit League contest versus the Nationals.
Mack was unavailable for a bit due to neck stiffness, but he's been cleared to return to action. The 23-year-old is 3-for-18 with one home run and a 2:6 BB:K this spring and is projected to open the season at Triple-A Jacksonville.