A trequartista is someone between an attacking midfielder and a second striker. Xavi's more of a central midfielder. He certainly wasn't at the tip of the midfield diamond--out of Spain's normal midfield six, Xavi plays ahead of Busquets and Xabi Alonso, but behind Iniesta, Fabregas, and Silva.
If anyone the closest Spain have to a trequartista is Fabregas, though he was really more of a false nine. The idea of a false nine is that you play an attacking midfielder or second striker, but there's no striker in front of him. This pulls the defenders out of position so you can get around them.
You might say that Iniesta, Fabregas, and Silva were listed as forwards. Actually, Spain didn't usually play any forwards. It might have been listed as a 4-3-3, but it was more of a 4-6-0 with three attacking midfielders. There's two reasons for this: one was that David Villa is injured and Fernando Torres has had shaky form for the past two years, and the other is that Spain has plenty of great attacking midfielders. Individually, David Silva, Andres Iniesta, Cesc Fabregas, and Juan Mata are all major stars and are (or were in the case of Cesc Fabregas and Arsenal) the main creative force for their respective clubs.
If anyone the closest Spain have to a trequartista is Fabregas, though he was really more of a false nine. The idea of a false nine is that you play an attacking midfielder or second striker, but there's no striker in front of him. This pulls the defenders out of position so you can get around them.
You might say that Iniesta, Fabregas, and Silva were listed as forwards. Actually, Spain didn't usually play any forwards. It might have been listed as a 4-3-3, but it was more of a 4-6-0 with three attacking midfielders. There's two reasons for this: one was that David Villa is injured and Fernando Torres has had shaky form for the past two years, and the other is that Spain has plenty of great attacking midfielders. Individually, David Silva, Andres Iniesta, Cesc Fabregas, and Juan Mata are all major stars and are (or were in the case of Cesc Fabregas and Arsenal) the main creative force for their respective clubs.