The Blues were defeated 1-0 by the Bundesliga side, with Karim Adeyemi’s second-half strike seeing Dortmund take a slender lead to Stamford Bridge for the return leg next month.

Despite the defeat, the Blues performed well and created plenty of opportunities to win the game and the lack of a cutting edge in front of goal is what disappointed Kai overall.

‘It’s frustrating to lose because I thought we played quite well,’ Havertz said when speaking post-match.

‘We came here to win the game, or at least draw, but in the end we have lost and it’s just really frustrating for us.

‘Their goal was a mistake from us and we knew that Adeyemi is a fast player, especially on counter-attacks. So that was disappointing.

‘We created plenty of chances and on another day, we could have scored a couple of goals and the tie would look so different.

‘I don’t think we should be too unhappy with our performance because we created the opportunities, but it’s just frustrating that we couldn’t take any of them. We have to look at that and try to improve on that front.’

Graham Potter handed Chelsea Champions League debuts to Joao Felix, Enzo Fernandez and Mykhailo Mudryk, with the trio all impressing.

Havertz believes the new signings are beginning to gel well with the team and that getting back to winning ways is just around the corner.

‘We have had a lot of new players join in this window and I think you can definitely see us improving and getting that chemistry with one another now,’ added the German.

‘This was another step forward, even though we lost. The result of course is the most important thing and it wasn’t what we wanted, but I think we showed some good signs – especially in the second half – and we need to build on that.’