The Nationals recalled Alvarez from Triple-A Rochester on Monday.
Alvarez will start Monday's game in Philadelphia. The left-hander had not made an appearance for Rochester after being sent there one week ago, so he'll be taking the ball Monday on six days' rest. Alvarez has logged a 4.06 ERA, 1.51 WHIP and 58:28 K:BB over seven starts and eight relief outings with the Nationals this season.