Aurelien Tchouameni and Eduardo Camavinga failed to show the quality they have done in training during Real Madrid's 2-1 win at Almeria on Sunday, according to boss Carlo Ancelotti.
Madrid fell behind to Largie Ramazani's early strike at the Power Horse Stadium in their opening LaLiga game of the season, but they drew level thanks to Lucas Vazquez's goal in the 61st minute.
They then sealed all three points with 15 minutes remaining when substitute David Alaba curled a sumptuous free-kick past Fernando Martinez from 25 yards with his first touch.
Tchouameni, who joined from Monaco in June for a fee that could rise to €100m, and Camavinga started alongside Toni Kroos in midfield, but both struggled to make an impact.
Camavinga was replaced by Luka Modric at half-time, while Tchouameni did not last an hour before he was substituted for Eden Hazard.
Neither player made more than a single key pass – well short of the team-high four that was achieved by three other players – with Ancelotti suggesting the pressure of playing for such a prestigious club affected the pair.
"For me, [Antonio] Rudiger played a good game," he told Movistar.
"The youngsters didn't play like they usually do. For what they do in training they deserve to play. They haven't done anything wrong, but they can do better.
"They are young and the shirt is heavy. It is a toll we pay, but we pay it with pleasure.
"I removed Camavinga because he had a card and could be a danger in a team that played on the break.
"It was normal to suffer because we've complicated the game with a defensive error. From then on it has cost us a lot."
Hazard has endured a torrid time with injuries since he joined from Chelsea in July 2019, but the Belgium international is hoping to play an important role this season.
Ancelotti is not sure where his best position will be, given Vinicius Junior's continued brilliance on the left of the front three, but the Italian expects him to feature regularly.
Asked where his best position is, Ancelotti said: "I don't know, I have to think about it. Hazard is a midfielder. We have to bear in mind that Vini really likes the wing.
"Today he tried to find a lot of the right central defender, where the spaces were very small. Hazard when he came on was good, he's training well and I think he's going to have minutes this season."