Cesar Azpilicueta called for Chelsea to be realistic with Callum Hudson-Odoi but acknowledged the teenage winger is set to be a "massive player" for the club.
Hudson-Odoi has reclaimed his place in the Chelsea team after returning from a ruptured Achilles, starring against Newcastle United last week and then making his first Champions League start away at Ajax.
The England international was less effective in Amsterdam on Wednesday than he had been in recent weeks, but Frank Lampard's men earned a precious 1-0 away win.
Club captain Azpilicueta was not concerned by a quiet showing from Hudson-Odoi, recognising the inconsistency that comes with a young player who still has just six Premier League starts to his name.
Azpilicueta said: "We don't have to forget that Callum is 18 years old and his progression in the last 12-15 months, with an injury in between... We have to be realistic.
"The way he worked for the team, the way he always showed the ability to get the ball, to dribble, not to have any fear to hide in between the full back.
"I think Callum is a very important player for us. He's going to be massive player in the future for Chelsea but we have to accept the progression.
"Still, to be 18 years old and the way he's playing is amazing. The only way I can see is by his work rate going up and improving."
Hudson-Odoi is one of a number of academy graduates now in the Chelsea first team, with Fikayo Tomori, Mason Mount and Tammy Abraham earning international call-ups this season while Reece James is also breaking through.
Azpilicueta has been pleased with both the way the young stars are adapting to their new demands and with the support they are receiving from more experienced team-mates.
"The players who have more experience in these games try to help the young lads," he said. "For some of them, it's the first year in the Premier League, the first year in the Champions League.
"So we have to be a help for all of them, use our experience to keep them confident and make them express themselves the way they have been doing in the academy.
"It is very important for them to feel confident. It is the way we are working.
"But a lot of credit goes to them because they are good lads, they listen, they want to improve in every training session and learn from the more experienced players, the manager and the staff. It is the right way to keep improving."