Salomon Kalou believes Chelsea can win the UEFA Champions League ahead of the second leg of their quarter-final with Benfica on Wednesday.
The Blues have one foot in the semi-finals ahead of the home leg having left the Estadio da Luz with a 1-0 victory earlier this week.
Barcelona or AC Milan await them in the semi-finals on 18th April if they can see off Benfica at Stamford Bridge but goalscorer Kalou knows Chelsea have a job to finish first.
"I think our worst enemy can be ourselves, thinking that we have done the most difficult part," Kalou said.
"We have to keep going, working hard. We have to prepare and try to score early and secure the victory at home.
"It's not finished yet. Benfica are a good team and we have to respect them. We have to play 100 per cent in the second leg if we want to go through to the semi-final."
Chelsea host Benfica with a precious away goal in the bank meaning any score draw at Stamford Bridge would see them progress.
"We know that scoring in the away game is always important, and we haven't conceded," Kalou added.
"It's still going to be a difficult game because Benfica are a great team, as they showed against Manchester United before, so we have to respect them.
"Winning the Champions League is possible, everything's possible.
"Given the team that we have, we know we can win against any club. We have to work hard as a team and continue to improve in every game."