Spain coach Vicente Del Bosque has admitted he is worried about David Villa's chances of competing at Euro 2012, only days after pledging to wait until the last moment before ruling out his injured striker.

Spain's bid to successfully defend their European title suffered a blow Tuesday when it was announced Barcelona defender Carles Puyol would likely be unavailable due to imminent knee surgery.

Now Villa -- dubbed 'King David' thanks to his 51 goals in 82 internationals -- could become the second high-profile name on Del Bosque's absentee list in Poland and Ukraine this summer.

He fractured his left tibia in Barcelona's Club World Cup semi-final win over Al Sadd in Japan on December 15.

And despite showing signs of recovering, his lack of match fitness once the Euro rolls around would give Del Bosque a selection dilemma.

"He is giving his all and recovering quickly, but he still has not played," Del Bosque said in comments broadcast on Cadena Ser radio Tuesday.

"We are on tenterhooks. We are worried because, of course, it is difficult for us to take someone who has not played one game."

Del Bosque had said Friday he would keep a spot open for Villa until the last moment: "We're obliged to wait until the last moment in David's case because he has been our most reputable goal scorer."

Barcelona defender Puyol, meanwhile, faces six weeks on the sidelines depending on the outcome of the exploratory knee surgery he is scheduled to undergo on Saturday.

The club said Puyol would need about six weeks to recover.