The former Arsenal midfielder thinks that the Red Devils may already be planning for van Gaal's departure.
Paul Merson has told Sky Sports that he would not be surprised if Manchester United decide to sack Louis van Gaal in the coming weeks, and appoint Jose Mourinho after the Portuguese was dismissed by Chelsea.
Despite guiding the Blues to the Premier League title last season, Mourinho was sacked after Chelsea made a dismal start to the campaign. The Stamford Bridge side are just one point above the bottom three following Monday's defeat to Leicester City.
And Merson believes that the Red Devils should act swiftly before the Special One heads elsewhere.
"LVG will be looking behind him. If it doesn't go well for United in the next week or two, I think they might look and think one of the best managers in the world is available, let's get him," he told Sky Sports.
While United are not enduring the kind of struggles that the champions are currently, their style of football has come in for criticism this season. And while their methodical build-up play would be much more acceptable if the Red Devils were dominating the division, they find themselves six points off the lead.
Like Mourinho, van Gaal boasts an impressive managerial record. But as Mourinho now knows all too well, sometimes a change of ideas and philosophies is required to keep a team on track.