Cristiano Ronaldo joined Juventus this summer from Real Madrid in a £99million transfer.
The Portugal forward has won five Champions League titles, four of which have come in the last five seasons.
His other European crown came during his time with Manchester United but Juventus splashed the cash this summer in the hopes that Ronaldo could deliver the goods for them.
Ronaldo played for United between 2003 and 2009 before moving to Real Madrid.
Why was Cristiano Ronaldo sent off for Juventus?
He was shown a red card in the 29th minute against Valencia.
Ronaldo was involved in an innocuous-looking clash in the area and was stunned when German referee Felix Brych dismissed him.
The striker appeared to knock Jeison Murillo to the ground off the ball and was shown a straight red card.
Will Cristiano Ronaldo miss Manchester United clash?
As it stands, Ronaldo will miss a return to Old Trafford due to suspension.
Man Utd vs Juventus is scheduled for October 23.