Chelsea Youngsters Impress Zola  (Sky Sports)

Chelsea assistant manager Gianfranco Zola was full of praise for Fikayo Tomori and Mason Mount after the loanees faced them with Derby in the Carabao Cup on Wednesday night.

Tomori got off to a nightmare start against his parent club at Stamford Bridge as he scored an early own goal, but he rallied well while Mount also assisted a goal in the 3-2 victory for the Blues.

"[Tomori] was unlucky with the own-goal but the performance him and [his defensive partner Richard] Keogh put in was excellent, so he shouldn't feel bad, it happens," said Zola.

"It was an excellent cross and if he wasn't there [Alvaro] Morata would have scored. He played well and Mason Mount had an excellent game. It looks like they are in good hands, they are doing well and the coaching they are getting is excellent.

"We always keep in contact with them and we have people who talk to them and follow them. They are players we certainly keep an eye on and we hope they continue to improve like they have been doing."

Chelsea made eight changes from their win over Burnley in the Premier League on Sunday and Zola admits their performance wasn't entirely up to scratch.

The Blues twice took the lead in the first half through own goals from Tomori and then Richard Keogh, but Derby battled back with goals from Jack Marriott and then Martyn Waghorn, before Cesc Fabregas scored the eventual winner before the break.

"They really played well and surprised us, they played with a lot of quality," said Zola. '"Our passing wasn't as sharp as normal and above all in the last 15 minutes we lost control and the distances were too far, and when you give space to the players Derby have got it becomes difficult.

"We need to improve. It was positive in some ways but other things didn't work properly tonight."

Chelsea will face Bournemouth in the quarter-finals at Stamford Bridge, but Zola insisted that Wednesday night's game proved there are no easy games in cup competition in England.

"Even today should've been a routine win. In this country, in cup games, they can't be underestimated," he said.

"We can call it a friendly draw, but Bournemouth is not going to be easy for sure."