LONDON (AP)

Cristiano Ronaldo returns to Champions League action today in a bid to kick-start Manchester United's title defence after the club's jittery start.

The Portuguese winger, who scored 42 goals during United's double triumph in Europe's top club competition and the Premier League, is back to full fitness after an ankle operation.

The catalyst

After a 0-0 draw with Villarreal in a group which is searching for its first goal, the Red Devils hope Ronaldo will be the catalyst to a much needed victory against Danish side Aalborg.

Ronaldo scored in United's League Cup 3-1 win against Middlesbrough last week and in Saturday's 2-0 Premier League victory over Bolton.

Ronaldo faces an Aalborg defender who almost missed the game through a suspension he didn't deserve.

Wrong player

Michael Beauchamp was sent off in the 0-0 draw with Celtic in Glasgow but the referee had sent off the wrong player. When Aalborg appealed and UEFA realised that Michael Jakobsen had committed the foul that led to his red card, Beauchamp won a reprieve. He will now face United while Jakobsen serves the one-game ban.

"Luckily everything has been put to rights," the Australian defender said. "Apart from the referee, everyone could see it wasn't me but Michael Jakobsen who made the challenge."

"Now I'm available for a dream match which my parents are flying over from Australia for," Beauchamp said. "Strictly speaking our chances of winning are minimal. Instead we're viewing this match primarily as a great experience."