McClanahan isn't on the mound for the start of Tuesday's game in Miami for unspecified reasons, Tricia Whitaker of Bally Sports Sun reports.
The 25-year-old was scheduled to start Tuesday's contest, but instead it's Shawn Armstrong on the mound in the first inning against the Marlins. McClanahan is being evaluated by the training staff, per Marc Topkin of the Tampa Bay Times, so it appears to be an injury issue for the lefty. The Rays should provide an update on the situation in the near future.