Xavi has already played 60 games for club and country this season
Spain midfielder Xavi could miss the World Cup with a muscle injury.
The Barcelona star, 30, scored one goal and set up two in Saturday's 4-1 win at Villarreal but admitted afterwards that he has a 3cm tear above his calf.
"Xavi's playing with an injury that could see him miss the World Cup," said Barcelona boss Pep Guardiola.
Xavi, whose side are battling with Real Madrid for the Spanish title, added: "I'm carrying a number of aches but the team has a lot on the line."
Barca are four points clear at the top of La Liga but Real have four games remaining to the Catalans' three.
Xavi has contributed three goals and 13 assists in 32 league appearances for Barca, with whom he won the La Liga, Spanish Cup, Spanish Supercup, Champions League, Uefa Super Cup and Fifa Club World Cup titles last season.
He was also named player of the tournament after helping Spain win the 2008 European Championship.
Spain open their World Cup campaign against Switzerland on 16 June before also facing Honduras and Chile in Group H.