Mason appeared in 61 games in his first full season with the club this past year, posting a 33-18-7 record with a 2.50 goals-against average and .917 save percentage.
This is the second successive summer in which a key member of the Flyers core has suffered a hand injury.
Claude Giroux had to undergo surgery to repair a tendon in his index finger last year after a golf club shattered while on the course. Giroux struggled early in the year when it was likely difficult for the captain to get a good grip on the stick.
It's unclear if the injury will interfere with the beginning of training camp for Mason, though a source indicated that he should not be the case.
David Strehle is the Philadelphia Correspondent for The Fourth Period.