Juventus midfielder Miralem Pjanic has backed Gianluigi Buffon to prove he remains the best goalkeeper in the world despite two costly mistakes in recent matches.

Buffon presented Vitolo with a simple finish when he completely missed an interception during Italy's 1-1 World Cup qualifying draw with Spain on October 6.

The Juve captain fared little better on his return to club action on Saturday, as he allowed Jakub Jankto's shot to squeeze beneath his grasp to give Udinese the lead, before Paulo Dybala's double rescued a victory.

Pjanic, however, says the 38-year-old will produce his very best form when Juve take on Lyon in Tuesday's Champions League Group H encounter.

"Buffon is our captain. I don't think he's having a bad spell," Pjanic told a news conference. "He's still the world's number one.

"In a career, there are high points and low points - that's normal. But Buffon is playing and talking with us as normal so I don't think there's anything to say.

"He'll make the difference and prove he is the world's best."

Pjanic, who spent three years with Lyon before moving to Serie A with Roma in 2011, expects a difficult test at Stade de Lyon despite the home side having lost three of their last four matches.

"It's true that Lyon have had a tough period, but I know the players, the coach and how things are here, and usually these difficult times don't last very long," said the 26-year-old.

"That means it's a very difficult game for us. We have to give our best to qualify for the knockout stage.

"Nabil Fekir and Alexandre Lacazette can cause problems for a lot of teams, but we'll do our best to be more dangerous than they are."