Appel failed to make it out of the first inning during his start Sunday for Triple-A Lehigh Valley. His fastball was topping out at 89 mph, down from his typical 94-95 mph velocity in the early innings, Tom Housenick of the Allentown Morning Call reports.

EDGE Analysis

The decreased velocity is a concern as it could be a sign Appel is not fully healthy. He has really struggled of late, allowing 15 runs in his last four starts while walking 11 and striking out 17. Zach Eflin and Jake Thompson are likely ahead of Appel for an opportunity in the majors the next time the Phillies need a starting pitcher.

Appel was promoted to Triple-A Fresno on Wednesday, Evan Drellich of the Houston Chronicle reports. The top overall pick from the 2013 draft class hasn't had overwhelming numbers at Double-A Corpus Christi this season with a 4.26 ERA to go with 49 strikeouts and 23 walks. Appel has also given up seven home runs in his 63.1 innings of work this season and will now head to the Pacific Coast League to play with the Astros' Triple-A affiliate in Fresno.

Through seven starts for Double-A Corpus Christi, Appel is 3-0 with a 4.70 ERA, 1.63 WHIP and 23:14 K:BB over 30.2 innings. Appel opened 2015 with two consecutive two-hit outings (both wins), but he's struggled in five starts for Corpus Christi since then. While fellow top overall pick Carlos Correa was promoted to Triple-A Fresno last week, Appel is unlikely to follow him any time soon, as he has yet to build any consistency at the Double-A level.