A run of injuries derailed the athletic career of Mark Gallagher, an athletic 6-5 forward from New York.

Gallagher was considered Georgetown's top recruit of 1971 and started on the last all-freshman team in 1972. Gallagher saw limited time as a freshman, however, breaking a finger early in the season. Of the five recruits of the high school class of 1971, Gallagher was the only one that joined the varsity in John Thompson's debut year, averaging 8.7 points per game and earning all-tournament honors at the 1972 St. Louis Classic.

A player who Thompson once called his "biggest surprise" for the 1972-73 roster suffered an ankle injury which limited his effectiveness down the stretch, and by his junior season was unable to play at all because of a chronic back injury. According to the HOYA, Gallagher opted for disc surgery in 1974, and made an attempt to rejoin the varsity in 1975, but was physically unable to do so.

Following Georgetown, Gallagher earned a law degree from Fordham and enjoyed a successful career as a attorney in New York.