Portugal are second-bottom in their Group H after a draw at home to Cyprus and losing to Norway. "We're not where we should be," conceded Ronaldo, who missed both ties because of injury. "Now there isn't much room for error - we have to win."
Ronaldo said he was satisfied with his performance for Real Madrid. "Madrid are getting better and better, we're growing and the team is improving on several fronts," he said.
"We have to continue like that to go after La Liga. We mustn't just worry about Barcelona because there are other teams doing very well, like Valencia."
Los Che are leading La Liga with 16 points from six games, two points ahead of third-placed Real Madrid. Barcelona are a further point back in fourth.