Chelsea head coach Frank Lampard insisted Mason Mount started at Manchester United "on absolute merit" following criticism from Jose Mourinho on Sunday.
New Sky Sports pundit Mourinho questioned Lampard's decision to start the inexperienced Mount and Tammy Abraham at Old Trafford after Chelsea lost their Premier League opener 4-0.
Chelsea captain Cesar Azpilicueta said Abraham and Mount deserved to be in the side, with the latter making his Premier League bow in what was also Lampard's first match as manager in the top-flight.
And speaking ahead of Chelsea's Super Cup match against Liverpool in Istanbul on Wednesday, Lampard said 20-year-old Mount started on merit, adding he has "no fears" to field young players.
"With regards to the squad and picking experienced or inexperienced teams, I completely pick the best team to win the game regardless of age," said Lampard. "It's very important to have a competitive team.
"If young players have shown what they can do in training, and deserve their chance, for example Mason Mount deserves his chance completely on absolute merit as opposed to age, I will have no fears to play young players because it's important for a club like Chelsea that we do that.
"They need to deserve their chance. In terms of how we set-up as a team, I liked our aggressive off-the-ball work against United, we won the ball back a lot, and it was more that we didn't finish off our opportunities that we got from that that lost us the game.
"We have to be adaptable, respect the strengths of the opponent, and Liverpool is a different challenge than United. It doesn't mean we are prepared to concede ground or defend our own box, but there may be subtle changes in how we approach.
"The main thing that has to stay is the intensity of our work-rate to win the ball back."
Meanwhile, N'Golo Kante was only deemed fit enough to come off the bench on Sunday, and Lampard revealed the midfielder will need to be assessed before Wednesday's match after picking up another knock against United.
"The selection of Kante on the bench was purely because he's had an injury in pre-season and missed a big part, so he wasn't ready for the game," Lampard added.
"I'm very aware of how important he is for us as a player. He also picked up another small injury in the game, which is a danger if you try and bring players in, so we are assessing that.
Willian and Antonio Rudiger have also travelled with the squad to Istanbul, but Lampard confirmed the duo will be on the bench.
Azpilicueta: We trust Tammy
Chelsea captain Cesar Azpilicueta says he trusts Abraham and has backed the 21-year-old to keep improving.
Abraham hit the post with the score at 0-0 against United, and Azpilicueta said the squad will continue to encourage the forward.
"I've known Tammy for a long time, when he was in the academy I saw him a lot of times. I saw his improvement," Azpilicueta said.
"We are talking about a player that has trained towards being in the Chelsea first team since he was very young.
"After two loan spells he has the chance here and deserves it. He did an amazing job last season at Aston Villa and worked hard in pre-season.
"He had the chance to start on Sunday and was very close to starting well. We need to keep encouraging him to keep doing his job.
"At this age the only way will go is up, he will keep improving and we trust him. We know that to be a striker at Chelsea demands a lot, but I am confident. Hopefully he will give us a lot of success - he is a great talent and has a great work-rate."
Chelsea go on to face Leicester in the Premier League on Sunday - live on Sky Sports - following their return from the Super Cup.