Manchester United signed the 20-year-old in a £7.4million deal last summer, but the striker failed to make an impacts during his first season at Old Trafford.
“I was happy to come to the best team in Turkey,” he said, according to The Daily Mail.
“I want to prove that Ferguson was not wrong by hiring me.
“He relied heavily on me, but unfortunately I could not show my value and I want to do this in Besiktas.”
