Gallagher (knee) has appeared in each of the Phillies' last three Grapefruit League games, going a collective 1-for-4 with an RBI.
Gallagher was scratched from the Phillies' lineup ahead of Saturday's spring training game versus Miami due to a right knee contusion.
Gallagher signed a minor-league contract with the Phillies on Sunday that includes an invitation to major-league camp, Matt Gelb of The Athletic reports.
Gallagher elected free agency Friday.
Gallagher was designated for assignment by the Guardians on Monday.
The Guardians activated Gallagher (concussion) from the 7-day injured list Thursday, Zack Meisel of The Athletic reports.
Gallagher was placed on the 7-day injured list with a concussion Thursday, Zack Meisel of The Athletic reports.
Gallagher is starting at catcher and batting ninth Friday versus the Diamondbacks.
Gallagher is hitting ninth and behind the plate for Saturday's game against the Mariners.
Gallagher had his contract selected by the Guardians from Triple-A Columbus on Thursday.