Louis van Gaal has branded 's tactics at boring.
Van Gaal, still hurt by the handling of his sacking in 2016, claimed his style of play was more attractive at Old Trafford.
'We played football that was quite all right,' Van Gaal told . 'But it's not football that is appreciated in England.
'Right now, looking at United, I have to conclude Mourinho is not being criticised while it's far more boring football. What United produce now is defensive football.
'I always played attacking football. The proof is that the opposition were always parking the bus. They don't do that now because Mourinho plays so defensive.'
Mourinho was criticised for United's tepid display during defeat by rivals Manchester City on Sunday, which opened up an 11-point gap at the Premier League's summit.
Van Gaal - whose side only scored 49 league goals in his final season - insisted he does not hold a grudge against his predecessor.
'He is not an awful man,' the Dutchman added. 'I think he is a sympathetic guy. He was my assistant at Barcelona.
'I worked with him and what Mourinho did is what often happens in football.'
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