Cristiano Ronaldo may decide to end his playing career after seeing his dream of winning the World Cup dashed, says his former Manchester United team-mate Patrice Evra.

Ronaldo was used only as a substitute for the final two games of Portugal's campaign in Qatar, which ended with a surprise 1-0 defeat to Morocco in the last eight.

The five-time Ballon d'Or winner became the first player to score in five different editions of the World Cup last month, but all eight of his goals at the tournament have come in the group stage.

Ronaldo has been strongly linked with Saudi Pro League side Al Nassr since his United contract was terminated last month, but Evra believes he may hang up his boots.

"When I talked to him, we didn't talk especially about what he's going to do next. I don't know. I don't know if Ronaldo will retire," Evra told Sky Sports News on Friday.

"Sometimes at the end of your career you think, 'okay, I think it's time to stop', especially when you're not in the starting eleven with your national team. 

"Ronaldo wanted to play and be fit to win the World Cup with his country, this was his dream. Now he doesn't have that dream, I don't talk for Cristiano, but I won't be surprised if he retires. 

"Now, everything Ronaldo does, he's a bad person and a bad player or whatever, so I wouldn't be surprised if he decides to retire."

Ronaldo's great rival Lionel Messi has the chance to cap his career by lifting the World Cup for the first time on Sunday, having helped Argentina to the final with a series of talismanic displays.

Some have suggested Messi must win the World Cup to be considered the greatest player to have played the sport, but Evra feels the Argentina captain has already secured that status – alongside Ronaldo.

"He needs to win this World Cup? No. Him and Ronaldo are already the greatest," Evra added.

"Why does Messi need to win this World Cup? I think this is for the Argentina players to put him on the same level as Diego Maradona.

"Even when they say Messi does not have a good record with Argentina, he already played six finals with them. The debate is not whether Messi can be the greatest, he's already the greatest.

"But guys, let's not forget, Messi is the greatest and Ronaldo is the greatest, too. People have different opinions, and Ronaldo is there.

"It doesn't matter if he doesn't play the final, he's still the greatest. We have to respect every different opinion."