GELSENKIRCHEN, Germany - Schalke 04 must produce a big performance if they want to live with Jose Mourinho's Chelsea on Tuesday in the Champions League, the German's boss Horst Heldt has insisted.
Schalke face back-to-back clashes in Europe against Chelsea as Tuesday's match at Gelsenkirchen's Veltins Arena will be followed by a trip to Stamford Bridge on November 6.
Having won both of their Group E matches against Steaua Bucharest and FC Basel, leaders Schalke face a big test of their mettle against second-placed Chelsea.
The Blues crashed to a shock 2-1 defeat to Swiss champions Basel at Stamford Bridge in their opening match, but Schalke have suffered from erratic form this season.
Having laboured to a 3-2 win at Bundesliga bottom side Eintracht Braunschweig on Saturday, Schalke twice came from behind before Roman Neustaedter's 91st-minute winner.
"If we want to survive against Chelsea, we desperately need an improvement in individual performances," fumed director of sport Heldt.
The Blues' boss rates 2012 Champions League-title winners Chelsea as "top favourites for the title" and insisted Schalke need a "much better performance than in Braunschweig".
Schalke are hoping to welcome back goalkeeper Timo Hildebrand from a back injury, while US midfielder Jermaine Jones and Ghana star Kevin-Prince Boateng should be fit after knee injuries.
But Schalke look to be without defensive midfielder Marco Hoeger, who twisted his knee against Braunschweig.