Cresswll told West Ham TV: We knew it was going to be tough going to Leverkusen as they're a really good passing side, possession-based and don't force any balls, so it was tough at times holding on, but we hung in there for 83 minutes so it was really frustrating to concede a first goal and then a second as well.
Look, it's only half-time and we have to stay positive. It's another big European night at London Stadium and we need everyone together to try and turn the tie around. We've been in these type of ties, one-nil down, like Sevilla a couple of years ago, and we brought them back to our place and beat them, so we need another big night.
They're a really good side and unbeaten in 42 games, so we've got to go back to the training ground, dust ourselves off and play on Sunday and then go again on Thursday."
He added: We've got some massive games in the Premier League to come and we want to finish as high up the table as we can and get back into those European spots.
It's certainly up for grabs as there are only six games left for us now, and on Thursday night we want to get through into the next round."