Cristiano Ronaldo is doubtful for Real Madrid's trip to Levante on Sunday after picking up an ankle injury against Dinamo Zagreb in mid-week. The Portugal international was on the receiving end of some strong tackles in his side's 1-0 Champions League victory. Ronaldo's ankle needed to be stitched after the final whistle. The attacking midfielder will now have to pass a late fitness test before being named in Real Madrid's squad. The 26-year-old has started the 2011-12 La Liga campaign strongly, netting four goals in two games so far. Los Blancos lead the early La Liga table on goal difference from Valencia and Real Betis. All three boast a 100 per cent record from their opening two fixtures while defending champions Barcelona have four points from a possible six.