Mourinho was sacked by Chelsea on Thursday following a disastrous start to the campaign.
Van Gaal is currently under pressure at Man United following back to back defeats against Wolfsburg and Bournemouth and Merson insisted the club will be keeping their eye on Mourinho.
“If it doesn’t go well for Man United in the next week or two, I think they might look and think, ‘One of the best managers in the world of football is available. Let’s get him’.”
Mourinho’s reputation has undoubtedly been tarnished by his disastrous season at Chelsea. He threw his players under the bus, disrespected the club’s staff and his general conduct was appalling.
However, the fact remains that he is a proven world-class manager who has won trophies at every club he has gone. While United may prefer someone who provides more of a long-term option, the club should seriously consider Mourinho as a replacement if they do get rid of the Dutchman.