MANCHESTER - Cristiano Ronaldo's involvement in Manchester United's pre-season tour of Asia next month is in doubt following reports the Portugal winger could need a hernia operation.

MANCHESTER - Cristiano Ronaldo's involvement in Manchester United's pre-season tour of Asia next month is in doubt following reports the Portugal winger could need a hernia operation.

Ronaldo suffered a groin injury in the latter stages of his country's 2-1 win over Albania in a World Cup qualifier on Saturday.

According to media reports, the problem could require surgery to correct. An operation would cast doubt on whether Ronaldo would be able to start pre-season training with the rest of the United squad on schedule and, as a consequence, reduce the chances of him travelling to Asia.

United are due in Malaysia for the opening match of their four-country tour on July 18. They are also due to play in Indonesia, South Korea and China. - Sapa-AFP