The Montreal Canadiens forward will return to the lineup on Sunday against the Anaheim Ducks.
Gallagher was healthy scratched for the first time in his career in Saturday’s loss to the San Jose Sharks.
The 33-year-old has appeared in 64 games this season, putting up six goals and 14 assists with a minus-one mark.
Defenceman Arber Xhekaj is also back in Montreal’s lineup on Sunday.
Zachary Bolduc and Jayden Struble will be scratched in favour of Gallagher and Xhekaj.
Jacob Fowler will get the start in between the pipes on the second night of a back-to-back.