Real Madrid can sweep away concerns they have lost their edge when they square up to Monaco in the first leg of their Champions League quarter-final on Wednesday.

Whichever club comes through the tie will have a trip to London to look forward to in the semi-finals, with Arsenal taking on Chelsea on Wednesday in the first instalment of a derby tie for the right to face them.

Real have had a miserable week after a dramatic extra-time defeat by Real Zaragoza in the final of the King's Cup last Wednesday robbed the nine-times European champions of the chance of an historic treble.

The exertions of that defeat, and the defensive frailties exposed during it, were to blame for the 4-2 defeat at Athletic Bilbao which left the 'galacticos' just a point ahead of Valencia in the Spanish Primera Liga after the weekend's action.

But if there is talk of crisis at the Bernabeu, Monaco too have been a pale imitation of the side that sailed through the opening half of the season.

Europe was put on alert by their astonishing 8-3 destruction of Deportivo Coruna in the Champions League in November and by January they held a 10-point lead at the top of French Ligue 1.

Last weekend's 1-1 draw at home to Sochaux, however, saw Didier Deschamps's team overhauled at the top of the table by champions Olympique Lyon.

If domestic form is any indicator of European success then Arsenal should have the measure of Chelsea.

Arsenal have played the best football in England this season and, unlike Real or Monaco, have shown no signs of letting up as they chase a treble of their own.

Nine points ahead of Chelsea at the top of the English premier league, Arsenal can set a record of 30 successive top-flight matches unbeaten from the start of a season against Manchester United on Sunday. The following weekend, they face United again as the holders bid to reach a record fourth straight FA Cup final.

At Chelsea, the Roman Abramovich revolution has yet to fully iron out the inconsistency that has driven their supporters mad for generations and the Champions League is their last realistic chance of a trophy this year.

Add in the instability created by the constant swirl of rumours about the departure of coach Claudio Ranieri, and the fact that Chelsea have already lost three times to Arsenal this season and things look pretty bleak for the west Londoners.

But the faustian pact Chelsea fans sign up to trades defeats on wet Wednesdays to mid-table strugglers for the occasional glorious victory against all the odds -- like beating Arsenal for the first time in 16 games and more than five years.