Three-time World Player of the Year Cristiano Ronaldo insists he will have a "spectacular" season despite a slow start to the campaign caused by knee ligament damage.

Ronaldo was sidelined for two months by a sprained left knee ligament picked up during Portugal's Euro 2016 final triumph over France, forcing him to miss Madrid's first three games of the season.

He has scored just once in four La Liga games since making his return, but netted five times in Portugal's routs over Andorra and the Faroe Islands in the past week.

"I had a serious injury, I was out for two months. Now I am back and at the start I has less confidence, but bit-by-bit I am feeling better and more confident. I feel that I am back to what I was," Ronaldo told Madrid sports daily Marca on Friday.

"The season is very long and I am sure I am going to have another spectacular season."

Ronaldo is expected to sign a bumper new contract with the European champions until 2021 in the coming days and reiterated his intention to retire in the Spanish capital after becoming the club's all-time top goalscorer since joining from Manchester United in 2009.

"I didn't expect to be at Real Madrid for so long. I have already said that I want to retire here. It is the club in my heart.

"It gives me the opportunity to win individual and collective trophies. What I want most of all is to renew (my contract) with Real Madrid and continue here for many years to come."

Despite bagging two Champions League titles and winning the Ballon d'Or twice during his time with Real, Ronaldo has still only won one La Liga title in seven full seasons.

Zinedine Zidane's men need to get back to winning ways at Real Betis on Saturday after three consecutive La Liga draws have seen them cede top spot to Atletico Madrid on goal difference.

However, with still a two-point lead over champions Barcelona, Ronaldo is convinced Madrid can end a five-year wait to win La Liga.