The Phillies released Appel on Monday.
Appel (elbow) has made two Grapefruit League appearances to date, giving up an earned run on two hits and one walk while striking out two over two innings.
Appel has re-signed with the Phillies on a minor-league contract, according to the team.
Appel (elbow) was outrighted to Triple-A Lehigh Valley on Wednesday.
The Phillies recalled Appel (elbow) from Triple-A Lehigh Valley on Monday and placed him on the 60-day injured list.
Appel was placed on the 7-day injured list at Triple-A Lehigh Valley on Wednesday due to an elbow injury, Matt Gelb of The Athletic reports.
Appel was optioned to Triple-A Lehigh Valley on Wednesday.