McClanahan was invited to the Rays' big-league camp, Marc Topkin of the Tampa Bay Times reports.
McClanahan has yet to reach Triple-A and has only made four starts at the Double-A level, so he's unlikely to be in consideration for an Opening Day roster spot. The 22-year-old struggled to an 8.35 ERA in those four starts for Montgomery, though his 2.50 ERA in 17 starts and two relief appearances at the Low-A and High-A levels was quite strong.