Spain midfielders Thiago Alcantara and Koke have admitted they are growing tired of questions about Gerard Pique's role with the national team.

Pique was jeered by a number of fans at a training session on Monday due to his outspoken support of Catalonia's independence referendum.

Tensions have mounted between those in favour of secession from Spain and supporters of remaining a united country in the wake of last Sunday's vote, which was deemed illegal by the central government.

Hundreds of people are reported to have been injured during clashes with police, while Barcelona played their LaLiga match against Las Palmas behind closed doors as a show of protest against a refusal by authorities to postpone the game.

An emotional Pique described it as the worst moment of his career and suggested he would be willing to retire from international football if his support for the right to an independence vote proved too divisive.

Thiago, a former team-mate of Pique's at Barca, says he looks as committed to the cause as ever but is growing weary of the constant scrutiny of the centre-back's actions.

"He looks the same as ever," he told a news conference he attended alongside Koke. "Whenever I've been called up, he's had the same attitude, the same commitment and joy as ever.

"It bothers us because we come to play football. I haven't come to talk about anyone's life and neither has Koke.

"We don't want to talk. We just want to play football. That's the solution. Everyone has their personal opinion and we're here to talk about the national team, not about political and public debates."

Atletico Madrid star Koke also admitted the saga is proving tiresome but is confident the team will have the support of the crowd when they face Albania in Alicante on Friday. 

"On the inside, it's been the same. We're focused on the game against Albania," he said.

"It's a bit tiring talking about the same thing. We're professionals and we're thinking about football.

"It's a really important game in Alicante. I've always felt the support and affection of our fans. I'm sure we'll have that in Alicante."

Spain will qualify for the World Cup on Friday if they better the result of Italy, who host Macedonia.