The German coach is one of Europe’s brightest young managers and has been linked with a number of top jobs in the Premier League after taking his side to the semi-final of the Champions League last season.
Under Nagelsmann’s coaching, Werner netted 28 Bundesliga goals and earnt a £53million move to Stamford Bridge over the summer.
But so far Werner has only netted in one of his six Premier League games for Chelsea and Nagelsmann says his former charge feels there is a big step up compared to the Bundesliga – something he himself may experience one day.
Asked about the differences between English and German football, Nagelsmann said: ‘I’ve never been a manager or a player in the Premier League, so I could not compare it in detail to the Bundesliga.
‘But when I watch games of the Premier League I recognise that it’s a very tough and good league.
‘So perhaps it’s one of the best leagues in the world, I think that’s clear, but perhaps it’s the best league in the world.
‘But if I will be in the Premier League in the future, perhaps then I could compare it a bit more in detail and then you can ask me the question again and I will answer in a bit more detail.’
Nagelsmann has been linked with the Manchester United job whenever Ole Gunnar Solskjaer is under pressure and will get a chance to audition for the job at Old Trafford on Wednesday night when the Red Devils host Leipzig.