Nkunku opened the scoring in the eighth minute with a cool finish after a fine chipped pass from Joao Felix.

The forward soon added his second with a clever flick to divert Malo Gusto’s low cross into the net, before a Felix free-kick hit the post and bounced in off Barrow goalkeeper Paul Farman to give the Blues a 3-0 half-time lead.

Two minutes after the restart Pedro Neto scored his first Chelsea goal by tapping in after Mykhailo Mudryk’s pass across goal.

Nkunku completed his hat-trick in the 75th minute after tackling keeper Farman and passing the ball into an empty net.

Thanks to his first Chelsea treble, the 26-year-old Frenchman now has six goals in eight appearances this season for the Blues.

Nkunku was making his first start for the hosts since their opening-day defeat by Manchester City last month.

The Italian previously said the 27-year-old defender would “struggle” if he stayed at the club as he was made to train in what reports described as a ‘bomb squad’ of 15 players away from the main first-team group.

Internally, the group was called a ‘loan group’ but Chilwell has been reintegrated into Maresca’s squad since the transfer window closed after failing to secure a move.

When asked if Chilwell, Carney Chukwuemeka and academy duo Tyrique George and Josh Acheampong could feature in Tuesday’s third-round tie, Maresca said: “Yes, they are going to be in the squad tomorrow.

“Some of them, we will see if they will start, but if not we will have them on the bench and see if we can give them some minutes. It will be a chance, as we have done in the Uefa Conference League, so hopefully they can show a little bit themselves to get more minutes.”

Chilwell hasn’t played a competitive match since April last year and his future remains in question.

Malo Gusto has also returned from injury, while Maresca hinted Mykhailo Mudryk, Kiernan Dewsbury-Hall and defender Benoit Badiashile could start against Barrow, who are joint top of League Two but still 64 places behind Chelsea in the football pyramid.

But the Blues boss added the priority is the Premier League as Chelsea compete in five competitions this season, including the new expanded Club World Cup.

He added: “I don’t see, in this moment, any competition better than the other one.

“For sure, the main one is the Premier League always. It is the competition you try to do your best always. But in terms of, ‘this is the most important, this is not important’, that’s not for us. We need to take every game in the same way and then we see in the end if we are close to something and then go for it.”