Meulensteen spent over a decade at Manchester United in various roles, from the youth teams and reserves to coaching in the first team.
Speaking on BBC Radio 5 Live, the Dutch expert commented on the Red Devils' draw against Real Sociedad. Meulensteen's countryman Joshua Zirkzee scored the opener, but that was quickly cancelled out as La Real were given a penalty for Man United captain Bruno Fernandes' handball.
"If Ruben Amorim looks back there have been a few moments in the game to score more. I think if United had gone 2-0 ahead they would have seen the game out. That penalty brought Real Sociedad back into the game," he said.
Manchester United are all the way down in 14th place in the Premier League and some off the pitch moves by owner Sir Jim Ratcliffe have also come under criticism.
Meulensteen seems to think the Man United of today are far, far away removed from the successful Red Devils he was a part of.
"Manchester United has not been Manchester United since Sir Alex Ferguson left. It has been a constant decline. Not only that, but there's so many other things from Man Utd that causes uproar. It is a club in unrest - on and off the pitch," the coach said.