Former Portugal team-mate Deco has spoken of the ‘insane lengths’ that Cristiano Ronaldo goes to in training in order to get the best from himself.

According to the former Barcelona playmaker, it is Ronaldo’s endless pursuit of perfection that has made him the superstar he is today.

Deco was capped 75 times by Portugal and will be hoping that Ronaldo can help his country to the point they require against Denmark on Thursday to secure automatic qualification for Euro 2016 in France next summer.

Fernando Santos’ team recovered from the early shock of losing at home to Albania to win each of their subsequent matches in Group I and Deco says the national team captain brings unmatched levels of commitment to each training session.

“The guy isn’t well in the head, I’ve never seen anyone train like it, it’s not easy to be like that,” Deco told ESPN.

Deco also played alongside Ronaldo’s great rival Lionel Messi at Barcelona although the 38-year-old feels they are very different in their approaches.

He said: “Messi looks after his body as an athlete should, but what Cristiano does is incredible. He goes to insane lengths because he always wants to be the best in every way and he competes to win everything.

“It’s amazing to see both players in action, but impossible to make a comparison.”

Ronaldo has scored five times in five appearances for Portugal during their Euro 2016 qualifying campaign.

Portugal are 2.63 to lead at half-time against Denmark and win Thursday’s game. The Danes are 5.00 to earn their first victory in three Group I games in Braga.