The first Nigerian footballer to represent the club, Ighalo is now playing in Saudi Arabia with Al-Shabab.
Ighalo played 23 times for United in a year-long loan move. His best period came soon after joining, netting four goals in a fortnight.
His first goal came in his maiden start for the Reds, a tap-in at home to Club Brugge, and the 31-year-old drew great affection from the supporters for his committed and passionate approach to life at the club.
“All my dreams have come true,” Ighalo told Sky Sports this week.
“The greatest moment was when I scored my first goal at Old Trafford [but] just waking up every morning and going into training at Carrington was a thing of joy.