Ralf Rangnick faces biggest Manchester United challenge yet in 'master vs apprentice' clash

Manchester United have improved under Ralf Rangnick but are still taking time to adapt to the German's methods.

A run of so-called 'easier' fixtures have allowed Rangnick to experiment with his system a little at Old Trafford, with his trademark 4-2-2-2 formation ditched in favour of a 4-3-3.

Still, the results have not been great, with a disappointing FA Cup exit against Middlebrough and a draw against Burnley meaning any momentum that had been built has now been lost.

With United set to face the likes of Manchester City, Liverpool and Tottenham in March, Rangnick's men cannot afford to drop any more points in February, especially as fellow top-four hopefuls Spurs and Arsenal hold games in hand.

Saturday's home clash with Southampton may look a very winnable game on paper, but the prospect of Rangnick coming up against his former apprentice Ralph Hasenhuttl means it could be a trick afternoon.

Hasenhuttl took over from Rangnick at RB Leipzig in 2016 after the team were promoted to the Bundesliga, and he guided them to an incredible second-place finishing in their first season in the German top flight.

This showed his managerial nous and also his understanding of the style of play that Rangnick had brought to the team, something that doesn't bode well for United ahead of their clash with the Saints as Hasenhuttl will know better than anyone how to stifle Rangnick's side's game.

However, this also works in reverse and, as his former mentor, Rangnick will have a good understanding of Hasenhuttl's tactics, especially as he still deploys the 4-2-2-2 formation that he used at Leipzig.

Southampton have blown hot and cold under Hasenhuttl. They always seem to threaten to have a really strong season before hurtling down the