Chairman Karl-Heinz Rummenigge has ordered Bayern Munich to avoid "arrogance'' as they seek to complete a Champions League play-off victory over FC Zurich.
Bayern dominated the first leg at the Allianz Arena, running out 2-0 winners despite squandering numerous opportunities to make the second leg a formality. And Rummenigge is wary of taking the Swiss side lightly on home soil as Bayern chase a place in the lucrative group stage.
He said on Monday prior to the trip to Zurich: "If we make the mistake of playing with arrogance then it could be problematic. We have to score to make it 1-0 and then there will be silence, then there will be clarity.''
Star winger Arjen Robben, who curled home a wonderful second-half strike in the first leg to add to Bastian Schweinsteiger's opener, added: "It all starts again at nil-nil. We must not let up. We have to improve a lot.''
Villarreal face a tougher task as they seek to overturn a surprise 1-0 defeat at Odense.
Hans Henrik Andreasen scored the only goal last week after a slip by new signing Cristian Zapata, leaving the Yellow Submarine with plenty of work to do at El Madrigal in the return.
Spain international Bruno Soriano is in confident mood, though. He told UEFA's website: "There is so much at stake here that each one of us will give 100%. Our dressing room is very solid and we know that if we work hard during the game we will have plenty of chances to score.
"Even though we didn't find the net in Denmark, we have total faith in our attackers who are capable of scoring a lot of goals; we have a lot of scoring potential. We mustn't be overconfident, but I think in our own stadium things will be very different.''
Malmo coach Rikard Norling has backed his players to stage a stunning comeback and see off Dinamo Zagreb despite going into the second leg 4-1 down.
Norling said: "We're very strong with our fans behind us. If we can get a goal or two, you never know what might happen.''
Maccabi Haifa travel to Genk with a 2-1 advantage to defend while APOEL Nicosia will hope to overturn a 1-0 defeat to Wisla Krakow when they meet at the GSP Stadium in Cyprus.
Wednesday's action is highlighted by Arsenal's trip to Udinese.
The Gunners have had a miserable start to the new season with the 1-0 first-leg victory the only positive - Theo Walcott's early goal handing the home side a narrow advantage to take to north-east Italy.
Arsenal will not be able to turn to manager Arsene Wenger on the touchline, however, after UEFA today handed the Frenchman a two-game ban for breaching the terms of a previous Champions League sanction.
Young defender Carl Jenkinson believes it is time for the club's youngsters to stand up and be counted.
He told the club's official website: "There are a lot of young players in the squad, me included. But we are there for a reason - people believe in us - and all of us young ones have to step up to the mark and take responsibility, and that is what we will do.
"We are going to have ups and downs but that is part of football. We did well against Udinese and then things did not go our way with Liverpool. But we will bounce back.''
Also on Wednesday, Benfica host FC Twente with the tie poised at 2-2, Lyon take on Rubin Kazan with a 3-1 first-leg lead, Sturm and BATE do battle again after a 1-1 draw while Plzen will hope to preserve a 3-1 lead over FC Copenhagen.