Chelsea and Arsenal were both embarrassed last night at the hands of Porto and Olympiacos respectively, with the Gunners without a point from their opening two games.

Whilst the Premier League champions managed a win in their opening match, two sloppy goals meant that Jose Mourinho wasn't victorious against the side he won the Champions League with in 2004.

Arsene Wenger's decision to rest Petr Cech came under scrutiny as back up keeper David Ospina fumbled into his own net as Arsenal lost 3-2 at the Emirates.

More worrying however for Wenger will probably be how quickly his side lost the initiative after twice drawing level against the Greek side.

Following on from their opening defeat to Dinamo Zagreb, and with a double header against German giants Bayern Munich next, Arsenal's defeat could well be fatal already.

Like Arsenal, both Manchester clubs cannot afford another mistake after they were both beaten on the opening fixture. Whilst City were facing last season's beaten finalists Juventus, the Italian champion's poor domestic form this season, and a home advantage, meant that City's loss was a disappointing one.

They travel to Germany to take on Borussia Monche­ngladbach, who could be argued are the weakest side in what is still a tough group.

If City are to make it past the last sixteen for the first time then they will need to come back from away trips like this with points in the bag.

United's return to the Champions League was not a pleasant one as not only were they beaten by Dutch outfit PSV, they lost the in form Luke Shaw for the rest of the season with a broken leg.

Since then Louis Van Gaal's men have managed to climb to the top of the Premier League table, and like their City rivals they will also be facing German opposition tonight in the shape of Wolfsburg.

Last season all four English teams only lost 6 group games between them, after last night's results, this season's teams have already lost five. City and United will both be hoping that they won't be adding to that unwanted statistic tonight.