MADRID, June 8 (Xinhua) -- Spain midfielder Andres Iniesta suffered a muscle injury as his side romped to a 6-0 win over Poland in their last warmup game before the World Cup kicks off.

Iniesta, who has had a season affected by thigh injuries, asked to leave the pitch with five minutes remaining in a first half in which he had set up his side's first two goals.

Spanish Football Federation (RFEF) sources quickly said the player was not seriously injured, with Fernando Hierro, the Sporting Director of the RFEF insisting that "the change of Iniesta was just for precaution, because of a light strain, there is no problem," but Iniesta's problems this season mean there is cause for worry.

He missed the end of the season with a torn muscle in his right thigh, a fortnight after suffering a strain in the same area, and the same problem kept him out of last season's Confederations Cup and saw him sidelined for three months.

Bearing that in mind, the Barcelona midfielder has to be considered a doubt for his side's opening game against Switzerland on June 16.

The good news for Spain was that Fernando Torres made his first appearance following his knee surgery in April and celebrated his return with a goal.