The 23 year-old famously joined the north Londoners in a £16million deal on summer deadline day and has since gone on to net ten times for club and country – including a hat-trick against Galatasaray in the Champions League and a brace for England last weekend.
Ince, who made 281 appearances for Manchester United before moving to Inter Milan in 1995, believes the move could soon prove to be a costly error on Louis van Gaal’s part.
“When he left Manchester United it was a shock. He has got pace to get behind teams and create gaps for others to exploit,” the 47 year-old told BBC Radio 5 live.
“I think it was a bad, bad decision to let him go. He offers something different to what Manchester United have got.
“They haven’t got pace – (Wayne) Rooney is not the quickest, neither is (Robin) van Persie and (Radamel) Falcao is injured.
“Since he has gone to Arsenal his performances have been fantastic. I don’t think he has got anything to prove to Manchester United.”
Whether it was a mistake by the United boss could come to light this evening, as Arsenal face Manchester United in the pick of the weekend’s Premier League action.