Nkunku set for Chelsea debut against Sheffield United

Nkunku signed from RB Leipzig in July but required surgery on a knee injury he suffered in pre-season.

"Yes, he can be involved. That is very good news," Pochettino told a press conference.

"To be involved tomorrow and be in the squad and to feel the competition after the pre-season is good news for us. We need to be calm and quiet so not to put all the pressure on him. Now he's going to evolve, know the Premier League."

Chelsea have struggled with injuries since the start of the season and there was more bad news last weekend when three players went off injured during the 2-0 defeat at Everton.

Reece James, who already missed seven league games early in the season with a hamstring injury, picked up a similar injury against Everton and needed to be replaced after 27 minutes.

"I prefer not to talk too much now. He's a little bit down because he was very excited to come back," Pochettino said.

"How we built him back was step by step, it was in a perfect way, we tried to build his confidence and full recovery and for him it's difficult to accept, very frustrated."

Defender Marc Cucurella and keeper Robert Sanchez also picked up injuries in the Everton game, with replacement keeper Djordje Petrovic making his first appearance for Chelsea since signing from New England Revolution in August.

After playing the last six minutes of the Everton game, Pochettino is confident he can depend on the Serbian keeper.

"Of course, I have faith in all of my players," the manager said.

"He arrived at Chelsea because we believed he had great potential. Now after four or five months working with us is the moment for him to step up and feel good because we have the confidence in him.

"Now he's about to make his debut, at Stamford Bridge, and yes, we trust that he can perform in the way we want."

Pochettino spoke of the difficulties the squad has faced with so many injury setbacks.

"It's like when you live in a house and suffer problems and need to delay. That in football happens when you're involved in a project to build something.

"We need to build a structure and take more time. I have no doubt, in the end we are going to succeed."

After two consecutive away defeats, at Manchester United and Everton, Chelsea are 12th in the standings on 19 points and on Saturday host bottom club Sheffield United, who have eight points.