Eflin was placed on the 15-day injured list by the Rays on Tuesday with lower-back tightness, Marc Topkin of the Tampa Bay Times reports.
Eflin had pitched well in his first two starts of the season but evidently has battled through the back issue "here and there," he told Tricia Whitaker of Bally Sports Sun on Tuesday. Imaging on Eflin's back came back clean, so he should have a good shot to return when first eligible on April 23. Taj Bradley will come up to start in his place Wednesday versus the Red Sox.