Lucas Vazquez hopes Lionel Messi is fit enough to play for Argentina against Spain in Madrid on Tuesday.
The Barcelona star was ruled out of his country's 2-0 friendly win over Italy in Manchester on Friday due to a hamstring problem.
It remains to be seen if he will recover in time to tackle Julen Lopetegui's side at the Wanda Metropolitano.
And while some players would welcome the absence of such a deadly rival, Real Madrid's Vazquez wants Spain to be able to test themselves as thoroughly as possible.
"Argentina have great players… It looks like Messi is going to be doubtful right up until the last minute," he said.
"We always want to play against the best players; so if Messi plays, then even better."
Spain drew 1-1 with World Cup holders Germany in Dusseldorf on Friday, and the 2010 winners are now being considered among the pre-tournament favourites by some.
Vazquez, though, sought to dampen the growing expectations around the potential of the side.
He said: "We have to be realistic - we have a fantastic national team, with some of the top players around, but it's pointless discussing whether we are favourites or not.
"The only thing we can do is work hard, know where our virtues lie and make sure we arrive in the best possible conditions, after that we can try and win the World Cup.
"We're full of hope. We are playing well as a team, the philosophy is sensational… Now's the moment when we have to get down to hard work so that we are ready when our objectives come along. We're on the right path."
Of Messi's potential absence, Saul Niguez said: "Argentina has a great team. If Messi is not there, [Angel] Correa will be there, and he can [make the difference] at any moment," he added, pointedly referring to his Atletico Madrid team-mate.
"You have to be careful with any of them."