José Mourinho has warned tonight's opponents Basel that Chelsea are much improved from the side beaten in September as the Blues bid to advance to the Champions League.
Chelsea play at St Jakob-Park seeking a fourth successive win - following the defeat to the Swiss in the opening game at Stamford Bridge - to seal top spot in Group E for Mourinho's men.
Basel, meanwhile, sit third, one point behind Schalke, and to advance must match the German side's result against Steaua Bucharest before going to Gelsenkirchen and winning.
"If somebody has to feel the pressure, it's not us," Mourinho said. "It's Basel, because they are in a limited situation to qualify for the next round.
"They are under pressure and we are not. We can finish the job to qualify and Basel, even if they win, have to play a last final at Gelsenkirchen.
"For them, the situation is difficult. This shows clearly that, after the first match, we did our job and they didn't do theirs.
"This Chelsea is better than the Chelsea that played at Stamford Bridge. Hopefully we can continue the good run we've had in the Champions League and finish the job."