Thomas Tuchel is Chelsea’s 15th manager under owner Roman Abramovich. Here, the PA news agency looks at the situation facing the Blues’ first German head coach.

Who is Thomas Tuchel?

He’s the 47-year-old former Borussia Dortmund and Paris St Germain manager, whose middling professional career as a central defender was ended by injury aged just 25.

Why has he taken over at Chelsea?

Chelsea sacked their former midfielder and club record goalscorer Frank Lampard on Monday, with the Blues having slipped to ninth place in the Premier League table. Tuchel is the man charged with pulling off an immediate return to form.

What is expected of the new man at Stamford Bridge?

Champions League qualification as a bare minimum, so a top-four Premier League finish. In truth Chelsea’s board expect Tuchel to create a harmony and rhythm in the Blues’ bloated squad that Lampard had struggled with this season.

Why only an 18-month contract?

Tuchel has a history of clashing with club hierarchies, insisting he wants to coach and not play politics. Managing up is just as important as managing down at Chelsea though. A short contract allows an easy exit for either party, but also the option to extend at any point.

When will Tuchel get started?

He already has, having taken training on Tuesday night. And he will be in the dugout for Wednesday’s Premier League match against Wolves at Stamford Bridge.

What are the biggest early hurdles facing the new boss?

Tuchel must heal the wounds that always follow a managerial exit, bond a divided squad – and then on the pitch tighten up the Blues’ defence and instil a clear tactical identity.