Barcelona's 18-year-old superstar Yamal has not played since suffering a hamstring injury on April 22.

Spain coach Luis de la Fuente said earlier this week he is hopeful Yamal will be fit for his side's opening World Cup game against Cape Verde on Monday.

However, he is unlikely to start in Atlanta.

"Obviously players always want to play and the player we are talking about, you can just imagine how desperate he is to return," Karanka told reporters at Spain's training base in Chattanooga.

"It is his World Cup and everyone wants to help (the team).

"But it is Luis and the medical team that will decide the timescales."

Spain also have other injury concerns over Nico Williams and Victor Munoz, who along with Yamal did not travel to Mexico for Monday's 3-1 win over Peru in a friendly.

The 2010 winners also face South Africa and Uruguay in Group H.

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