Eflin was recalled from Triple-A Lehigh Valley to start Wednesday against the Nationals.
As expected, Eflin will rejoin the big-league rotation after a brief stay in the minors due to some roster maneuvering. The 24-year-old right-hander owns a 3.70 ERA, 1.13 WHIP and 91:22 K:BB across 17 starts (97.1 innings) with the Phillies this season. He'll face Stephen Strasburg (neck) in this one.