Galarraga made his debut with Montreal on August 23, 1985. During that season’s last six-plus weeks, he struggled, hitting .187 (14-for-75), with two homers, and four RBI, in 24 games. Galarraga had a promising start in , but it was interrupted, when he suffered a knee injury; at the time, he had already posted eight home runs and was leading all NL rookies with 25 runs batted in. Galarraga underwent arthroscopic knee surgery, on July 10. He was activated one month later, only to be re-injured the following day after pulling muscles in his rib cage. Galarraga returned to action in September, ending with .271, 10 home runs, and 42 RBI, in 105 games.