Thomas Tuchel stunned by Chelsea's Champions League defeat in Zagreb

Chelsea made a miserable start to their Champions League campaign as Dinamo Zagreb ruined Pierre-Emerick Aubameyang's debut with a shock 1-0 victory.

Thomas Tuchel's side were expected to cruise through Group E after being drawn with Dinamo, Red Bull Salzburg and AC Milan.

But their task might not be so simple after Mislav Orsic's first-half strike punished the Blues for another sloppy display in Zagreb.

"It's an underperformance from us. We have the same story as always. We have an OK start, we don’t finish our half chances, we don't feel it when the game is already there to put to bed in the first 15/20 minutes," Tuchel told BT Sport.

"Then we concede one counter-attack, which is far too easy, and from there we struggled.

"Too much to analyse. I'm a part of it. We are clearly not there, where we need to be and where we can be. So it's on me, it's on us, we need to find solutions. At the moment, everything is missing."

Having spent £250 million ($280m) on new signings since the end of last season, Tuchel is under pressure to deliver silverware in return.

But Chelsea's spending spree has yet to pay dividends, with no eye-catching performances in the Premier League and now three successive away defeats in all competitions.

It was a debut to forget for Aubameyang, who joined Chelsea in a £10.3m deadline-day deal from Barcelona just months after the acrimonious end to his time at Arsenal.

Defeat in Zagreb. @WhaleFinApp | #UCL pic.twitter.com/LIx51tiqNG

The 33-year-old had played for just eight minutes this season and only trained with Chelsea for the first time on Sunday.

Aubameyang recently suffered a fractured jaw during a violent robbery at his home, forcing the Gabon striker to fly to Italy to have a custom-made