The Rays placed Rodriguez on the 15-day injured list Friday, retroactive to Sept. 3, with a lower-back strain.
Rodriguez has given up two earned runs and struck out eight batters in 4.2 innings since making his season debut Aug. 24, but he'll now head back to the injured list after tweaking his back. Cole Sulser (back) was reinstated from the 15-day IL in a corresponding move to take Rodriguez's place in the Rays' bullpen.