The English coach was already under pressure with his side ending the calendar year in 13th position in the Bundesliga, but tonight's 3-1 defeat at home to Cottbus could well prove to be the final straw for the 2009 Bundesliga champions.

Wolfsburg found themselves three goals down at the interval with the goals coming from Nils Petersen (2) and Jiayi Shao.

Edin Dzeko replied for the Wolves in the 56th minute, but it was too little too late, perhaps also for McClaren.

Fellow Bundesliga strugglers Cologne were also knocked out on a night of giant-killing in the cup.

They were beaten 2-1 at home by local rivals Duisburg with Simon Terodde scoring the late consolation for the Goats after Stefan Maierhofer and Julian Koch had scored for the Zebras.

And Eintracht Frankfurt were also knocked out by second division opposition as Alemannia Aachen triumphed on a penalty shoot-out.

Aachen missed a penalty in a goalless 90 minutes before going ahead early in extra time, but Martin Fenin forced a shoot-out.

However, Alexander Meier missed his spot-kick for the Bundesliga side, who lost 5-3 with Benjamin Auer converting the final penalty.

Holders Bayern Munich followed up their 5-3 win over Stuttgart in the Bundesliga at the weekend with a 6-3 triumph over the same opponent at the same venue.

Goals from Andreas Ottl, Mario Gomez, Miroslav Klose (2) and Thomas Muller helped Bayern into the quarter finals, although Pavel Pogrebnyak (2) and Matthieu Delpierre made it interesting as they brought Stuttgart , who also missed a penalty, level at 3-3.

The hosts ended the game with only nine men as Khalid Boulahrouz and Delpierre both picked up two yellow cards, although Bayern midfielder Bastian Schweinsteiger tried to talk the referee out of showing the Dutch full-back red for a foul on him.

Franck Ribery then took the tally of goals between these two sides in the last four days to 17 with Bayern's sixth.