Cristiano Ronaldo could potentially miss the start of the World Cup if Portugal qualify after receiving the first red card of his international career during their 2-0 defeat to Ireland in a World Cup UEFA Qualifiers Group F fixture in Dublin on Thursday.

Portugal manager Roberto Martinez described the sending off as "a bit harsh" and insisted the five-time Ballon d'Or winner "had constant contact with the defenders, who were grabbing him. There was no violence -- he tried to push them away."

Ireland coach Heimir Hallgrimsson, meanwhile, dismissed Ronaldo's earlier claims that he influenced the referee, saying: "It had nothing to do with me unless I got into his head.

"This was just a moment of a little silliness for him I would say."

Ronaldo will miss Sunday's match against Armenia, where Portugal aim to seal qualification for next summer's tournament.