Cristiano Ronaldo is sweating on whether he has a lengthy injury setback ahead of this summer’s World Cup.The Portugal legend was forced off during Al Nassr’s 3-1 win over Al Fahya on Saturday.GettyRonaldo will undergo ‘urgent’ tests after he was forced off in Al Nassr’s latest win[/caption]Ronaldo appeared to pick up a muscle injury before signalling to the bench.He was in visible discomfort as he was replaced by Abdullah Al-Hamdan in the 81st minute.The 41-year-old could later be seen with an ice pack on the back of his knee.It came after he had uncharacteristically missed a penalty for Al Nassr earlier in the match.His effort from 12 yards went wide off the post with the score level at 0-0.That miss appeared costly as Al Fayha took the lead on the troke of half time.However, three second half goals for the visitors, including from Ronaldo’s replacement Al Hamdan secured all three points.Following the match, Al Nassr boss Jorge Jesus confirmed the forward will undergo ‘urgent’ tests on the issue.Jesus told reporters: “Ronaldo suffered muscle fatigue and the medical staff will urgently perform the necessary tests to determine his condition.”It will spark fears ahead of this summer’s World Cup, which is now just three months away.Portugal holds its breath as results on the Ronaldo tests awaitGettyRonaldo is looking to represent Portugal at a record sixth finals in North America this summer.The five-time Ballon d’Or winner has featured at the last five tournaments, dating back to his first in 2006.More to follow.