Madrid, June 29 (IANS): Former Barcelona defender Carles Puyol revealed he would get humiliated by an "unstoppable" teammate Lionel Messi in training sessions at the Spanish football club.

The former Barcelona captain retired from the game in 2014 after he and Messi shared six league titles and three Champions League crowns with the Catalan side.

The 37-year-old has recalled a time when he had to be told to tone down his physical approach during one training session when he discovered the true extent of the Argentinian's powers.

"In a mini one-on-one match, I told myself, 'I'm going to see if I can stop him’. It was humiliating. Pep Guardiola (the then coach) told me, 'Carles, don't injure him',” Puyol was quoted as saying by La Vanguardia on Sunday.

"I told Pep, 'If you don't want anything to happen, stop the session'. I tried everything but he always got past me at his own pace," he said.

Messi is currently in Chile where his Argentina side will face Paraguay on Tuesday in the semi-finals of the Copa America.

Puyol, who played 100 matches for Spain netween 2000-2013, believes the 28-year-old is even better now than he was during their time together dominating European football with Barcelona.

"He's head and shoulders above anyone I've seen. He's an alien. He's better now than he was four years ago because he reads the game better. He's unstoppable," Puyol concluded.