Marco Asensio will miss Real Madrids' Champions League opener against Apoel Nicosia on Wednesday night because of an infected pimple, ESPN have reported.
The 21-year-old missed training in the buildup to the game, and coach Zinedine Zidane has revealed that he has a "pimple... which stopped him pulling up his socks".
Asensio's absence will be mitigated by the return of both Raphael Varane and Cristiano Ronaldo, from injury and suspension.
The French centre-back has been sidelined by an adductor muscle problem, and has been named in the squad for the first time since the Spanish Super Cup second leg against Barcelona last month.
Ronaldo, meanwhile, has been serving a domestic suspension for pushing the referee after his sending off in the first leg at the Nou Camp.
Striker Karim Benzema is another absentee, out with a hamstring injury, and he has been replaced in the squad by youngster Borja Mayoral.
But despite the fitness concerns hampering the squad, goalkeeper Keylor Navas has stressed the importance of having Ronaldo back in the side.
"For us it is always good to have the best player in the world on the pitch," he said. "He always brings so much for us. It is good for him to be able to play tomorrow, as he has been a few games without playing.
"And also for us as a team. When he is on the pitch, normally he scores many goals. All games are different, but the motivation and ambition he has will be important for the team."
He added: "In Liga we have not been able to win our last two games. This is a nice game, a different tournament. We know that the path to trophies is not easy.
"There are always things we can correct, we know that, after every game we look at what we did well and what we did not. We will keep playing in our style, go out to win each game, we are very sure about that."