"Steven Gerrard's return to the Liverpool side in a fortnight will make it more difficult for us. We see him as the brains and the heart of the Liverpool side and his addition will be very important for Liverpool and much harder for us, even though Biscan and Hamman played very well in that role," said the Bayer boss.
"I felt that we were unlucky to lose by that margin, certainly to let in two goals from free kicks and with the first one not even the correct decision.
"I was disappointed with the fact that we conceded two goals from set pieces and both times our wall was at fault. The first time Freier moved out of the wall and Riise's shot went through the space and the second time the wall looked like training ground dummies, who are not able to jump.
"Liverpool were more aggressive and put us under more pressure but we still had very good chances, two from Ponte and one from Berbatov, he should certainly have scored when he was through on goal.
"After the break when we were two down our aim was not to concede any more, and when Hamann scored I felt that was a killer. but when we scored that was our lifeline.
"We have already beaten Roma, Real Madrid and Kiev by a 2-0 margin at home in the competition this season so we certainly know we can do it if we concentrate and make sure we do not concede another goal to Liverpool at our ground."