Manchester United have been left behind by Manchester City this season and major improvement will be required if they are to compete with Pep Guardiola's title-holders in 2018-19, according to former Red Devils defender Paul Parker.
United's 1-0 loss to West Brom last Sunday saw City seal top spot with five games to spare, a joint record indicating the relative ease with which they have marched to the championship.
Jose Mourinho's side are 13 points behind in second place and, despite coming from behind to beat City 3-2 at the Etihad Stadium to delay their neighbours' coronation earlier this month, supporters at Old Trafford have remained indifferent to the style of play on display under the pragmatic Portuguese coach.
Parker, who won the league title twice during Alex Ferguson's glittering reign, feels Mourinho's tactics are outdated in comparison to those being implemented across the city by former Barcelona and Bayern Munich boss Guardiola.
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He told the Mirror Football Podcast: "They have been a million miles apart, not just with points but with ideas and the way they want to play [has] gone out of the modern game.
"The changing of the game has worked in the favour of Manchester City. Manchester United haven't really moved forward in their game.
"It is very much very regimented in what they are trying to do. It could, in some times, guarantee some results, but not in today's football.
"It hasn't worked for Manchester United. Next season they need to change up their game for them to get anywhere near Manchester City."