Cristiano Ronaldo picks himself up and gets back to business in Serie A against promoted Frosinone on Sunday after his return to Spain in the Champions League ended in a tearful sending off against Valencia.

The former Real Madrid star collapsed dramatically on the pitch after being handed a controversial red card just days after his first goals for Juventus saw the champions keep their 100 percent record to pull three points clear at the top of the Serie A table.

Juventus beat Valencia anyway thanks to two Miralem Pjanic penalties.

And after securing a winning start to the European campaign which is their focus this season, the Turin giants look to keep their quest for an eighth straight domestic title on track with a trip to Frosinone.

Coach Massimiliano Allegri is confident that Ronaldo, 33, will be back to business against a side from outside Rome who are second from bottom of the league with one point.

“He was upset and he needs time to calm down. He needs to rise above it and focus on Sunday, even if these things leave a bitter taste in the mouth,” said the coach.

The champions will be without German midfielder Sami Khedira who suffered a thigh muscle injury in Spain.

Douglas Costa also suffered an adductor injury, but the Brazilian would have missed Sunday’s league game as he sits out a four-match ban for spitting last weekend.

“He’s picked up an adductor injury from virtually his first sprint,” said Allegri.

“Unfortunately I was expecting this because the last few days have been draining for him mentally.

“When these things happen, the risk of injury is very high. It was a tactical decision that he would only come on for the last 20 minutes, but that was still enough for him to get injured.

Inter Milan also return from Champions League duty on a high after a last-gasp 2-1 win over Tottenham in their return to Europe for the first time since 2012.

DON’T MISS | Fantasy Premier League Pundit Picks: Gameweek 6

But Roma fell 3-0 to holders Real Madrid in Spain with Napoli playing out a goalless draw at Red Star Belgrade.

Luciano Spalletti’s Inter scored two goals in a seven-minute spell, sparked by captain Mauro Icardi who scored his first goal of the season on his Champions League debut.

Inter — floundering in 15th in Serie A with just four points from four games — head to fourth-placed Sampdoria looking for just their second win in the fifth round of action.

“This result gives us self-belief around the work we are doing. Getting players like Icardi to break their ducks is fundamental, as we need his goals,” said Spalletti.

“We have many great players, though and sometimes we must learn how to win even without Mauro. We can’t have the same XI in every game.” Roma — last year’s Champions League semi-finalists — are reeling from their defeat to Real Madrid.

MUST READ | James Milner apes the Roberto Firmino look with elan

Eusebio Di Francesco’s side have not won since their opening game against Torino in August, and travel Sunday to Bologna.

“I’m concerned but I’m not pessimistic,” said Roma sporting director Monchi.

“I remain confident that the coach will find the right path.”

Serie A runners-up Napoli, three points behind Juventus, visit Torino after a lacklustre European stalemate in Belgrade.

“It’s a tie that leaves us bitter, but there’s no reason to be dramatic, there are another five games to go,” said Napoli coach Carlo Ancelotti.

Lazio host Genoa after their Europa League win over Apollon Limassol at the Stadio Olimpico, with AC Milan hosting Atalanta after Gonzalo Higuain scored the only goal against Dudelange in Luxembourg.

SPAL — who are three points behind Juventus in second — host Fiorentina, with Sassuolo, in sixth, hosting Empoli in Friday’s early match.

Fixtures (all times GMT)

Friday

Sassuolo v Empoli (18:30)

Saturday

Parma v Cagliari (1300), Fiorentina v SPAL (1600), Sampdoria v Inter Milan (18:30)

Sunday

Torino v Napoli (10:30), Bologna v AS Roma, Chievo v Udinese, Lazio v Genoa (13:00), AC Milan v Atalanta (16:00), Frosinone v Juventus (18:30).