Juventus playmaker Andrea Pirlo has suffered sprained knee ligaments and Italian media have predicted he will be out for around 40 days.

Juventus said in a statement that the 34-year-old Italian international, who limped off in the first half of Sunday's 1-0 win over Udinese, had undergone tests on Monday.

"These findings have shown the player has suffered a grade two injury of the medial collateral ligament (MCL) of the right knee," the Serie A leaders said.

The club did not give further details but media speculated that Pirlo would be sidelined until January, missing the top-of-the-table clash against AS Roma on the weekend of Jan 4-5.

Pirlo, whose role as a deep-lying playmaker makes him a rarity in the modern game, has enjoyed a second wind since joining Juventus in 2011 after 10 seasons at AC Milan and inspired them to two successive Serie A titles.

Playing just in front of the defence, he dictates the rhythm of the Juventus midfield with a remarkably unhurried style, threading pinpoint passes through the opposing backline.

He is also one of the game's greatest free kick specialists and celebrated his 100th appearance for Italy last year with a magnificent effort against Mexico in the Confederations Cup at Rio de Janeiro's Maracana.

He was the only Serie A player to be named on the 23-man shortlist for FIFA's Ballon D'Or Player of the Year award.