Ronaldo looks to bounce back

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."