Cristiano Ronaldo flying as Juventus face key January test - in pictures

Andrea Pirlo's Juventus face a key test of their ambitions to clinch a 10th consecutive Serie A title after a stuttering start which has left the holders sixth in the league.

Serie A returns after the mini-break with a tight January schedule, and Cristiano Ronaldo and his Juve team-mates looked to be relishing the prospect of playing again as they worked out in a training session.

Juventus host Udinese on Sunday before taking on three of the top four this month, with six Serie A fixtures in addition to Italian Cup and SuperCup commitments.

Juventus are sixth, 10 points adrift of AC Milan in top spot, but having played a game less.

After Udinese, Juve visit AC Milan in the San Siro next Wednesday before hosting fourth-placed Sassuolo in Turin followed by a trip to play Inter.

Despite topping their Champions League group, Juventus have struggled for consistency on the domestic front, relying on Ronaldo's goals with the Portuguese striker netting 12 of their 25 in the league.

In Serie A, they have six draws and six wins, falling to their first league defeat of the season 3-0 to Fiorentina at home before Christmas.

"Sometimes it happens we're not 100 per cent. Now we have to start again with desire, thinking about the mistakes we made and carrying out our project," said Pirlo.

The former Italy and Juventus star can take heart from the fact that in the 2015-2016 season, they were 12th after ten matches, but powered back to win the title.

"It's premature to talk about the title," said Milan coach Stefano Pioli.

"Juventus remain favourites, a team that in the last nine years have won as many titles and have many champions.

"But there is also Inter, who came within one point of Juve last year and spent a lot of money in the transfer market. In addition, Inter have no European commitments."