Speaking on Sky Sports, the Irishman said: "It is a big call. He has obviously seen something he doesn't like. But for those who have watched Manchester United recently, it's not a big surprise because both players have been poor. He has said 'enough is enough'. It's a big call, but I like to see it - he has put down a marker."
He added: "A move for Marcus [Rashford] would suit the player – a new challenge for him. He’s been there a long time. When you’re at a big club and your attitude is not right – and it hasn’t been great recently – sometimes it’s good to part ways."