MANCHESTER, England (AP):

As if there wasn't enough at stake when two of Europe's biggest teams go at it for a spot in the Champions League quarter-finals, there are even more reasons for emotions to run high at Old Trafford today.

While one of Manchester United's former stars - Cristiano Ronaldo - returns, the club's longest-serving player - Ryan Giggs - is expected to hit another milestone.

And then there's the game itself, with United and Real Madrid level at 1-1 following the first leg of the last 16 of the Champions League.

Marvellous Game

"As a European night I don't think you can get any bigger than this one," United manager Alex Ferguson said yesterday. "Two great clubs, with great histories and it's set up to be a potentially marvellous game."

It will be Giggs' 1,000th senior match, and Ronaldo's first at United since becoming the world's most expensive player in 2009 by swapping Manchester for Madrid for 80 million pounds (then US$131 million).

Despite having seen his star player leave the club, Ferguson had nothing but superlatives for Ronaldo, calling him a "supreme athlete".

"My biggest concern will be if he turns up," Ferguson quipped. "What do you expect when you play against a team with Ronaldo in it? You expect problems during the night and we have you to try to curtail that as much as we can, as best we can. It won't be easy."

And United has to be careful it doesn't get too distracted by Ronaldo to focus on its own game plan.

"If we go in wondering about the damage Cristiano can give us, then we will forget some of the things we can do ourselves," Ferguson said.

It was Ferguson who helped to turn Ronaldo into one of football's most lethal attacking forces during six seasons at United.

When Ronaldo left Manchester in 2009, few would have expected Giggs to still be playing at the highest level four years later.

But the 39-year-old Welsh winger remains an integral part of the team.

"You set out different goals at the beginning of your career," said Giggs, whose latest contract takes him up to the end of next season. "You want to get into the team, then you want to stay in the team, then you want to win things and you never think you are going to get to a 1,000 games.