Manchester United coach Ole Gunnar Solskjaer has joined those who expect veteran Portuguese striker Cristiano Ronaldo to continue playing at the highest professional level until he reaches 40.

Ronaldo has scored 4 goals since returning to his former club United from Juventus last August after an absence of 12 years.

Norwegian coach Solskjaer praised the outstanding fitness of Ronaldo, 36, who last week became the highest-paid player in the world, surpassing Argentine Lionel Messi.

Before United's match with Aston Villa in the English Premier League today, Saturday, Solskjaer said, "It will not be a surprise for me if he continues to play until he reaches 40 years. The way he takes care of himself is the basis for that, and it is the basis of everything with some genetic factors for sure."

"He has used all his physical energies to reach the level he currently has," Solskjaer added.

Ronaldo won the award for the best player in the world 5 times.

The Norwegian coach indicated that Ronaldo is still keen to win more titles and awards, as he has always, stressing that "he will continue (in the stadiums) as long as he is physically and mentally able to do so."

Ronaldo fitness secrets

Former Manchester United fitness coach Mick Clegg had revealed some secrets of Ronaldo's continued brilliance, and predicted that he would continue to play until he was 41 years old.

Clegg worked within the technical staff of Sir Alex Ferguson during the period in which Ronaldo played for Manchester United from 2003 to 2009, and he was one of those who formed the Portuguese star and influenced his structure and physical fitness at the beginning of his start to stardom in the Premier League.

Clegg justified his expectation that Ronaldo "trains a lot, is keen on recovery time and sleep, has knowledge of cooking, knows how to avoid stress, he pays a lot of attention to minute details, and this is not a secret."

Manchester United is in third place among the English Premier League teams, having achieved 4 victories and a draw once, but it is equal in balance with the top teams Chelsea and Liverpool.