Chelsea boss Thomas Tuchel urges patience over Kai Havertz

The 21-year-old is yet to live up to his hefty summer price tag, but boss Tuchel insisted that is of no concern as long as Chelsea steer him back to his best.

"It takes time and there is no short answer – if there was then I would go and talk to him to bring out his full potential," said Tuchel.

"What we know and what we can rely on is this potential in him, there is logic to show it on the pitch.

"For every transfer and change of club is different, sometimes you need more time to adapt, sometimes it is quick, sometimes it is a process.

"All we can do is push him, support him and give him what he needs and we will figure this out.

"He had a really good start with us and I have the feeling that I see a guy who is self-aware, humble and incredibly talented.

"There are no doubts that he will show those full qualities, and the sooner the better.

"Unfortunately he has missed training and matches for us, and hopefully he will come back in the next days.

"And I am convinced he will have a big impact."

Chelsea ground past Barnsley 1-0 at Oakwell on Thursday night to book an FA Cup quarter-final with Sheffield United.

Tuchel will restore a string of players to his line-up to host Newcastle in west London on Monday, determined not to hit the misfiring team that beat Barnsley with too much criticism.

"We don't need to be too harsh, we don't need to be too strict, but we need to be clear," said Tuchel.

"There are things that we can do much better than we did at Barnsley. We hardly managed to get into the opponent's box. It was very hard to escape the first press to put the game into the opponent's half.

"So we struggled for 45 minutes, the first half. The second half between 45 to 75 was our best period in the game where we had full control, where we could score.

"But still, in the last 15 minutes, where we could not escape our own half and we struggled to cope with the physical style of Barnsley in the last few minutes.

"That gave us maybe an awkward feeling in the end, because we couldn't keep that control."