On February 5, 2015, it was announced that Martínez had suffered a torn medial meniscus in his left knee during offseason workouts. Martínez underwent successful surgery on his knee, and was expected to rejoin the team by the start of the regular season. Martínez did start the season, but reaggravated the left knee injury a couple weeks into April and began to struggle at the plate. In a game on May 18, Martínez landed clumsily at first base while running out a ground ball, tweaking the knee again. The Tigers put him on the 15-day Disabled List the next day. At the time, Victor was hitting .216 with just four extra-base hits (3 doubles, 1 home run) in 111 at-bats. He hit particularly poorly from the left side (.141 average in 85 at-bats), being unable to put weight on his back knee without pain. Victor returned to the Tiger lineup on June 19 in a game against the New York Yankees.