The Blues won Europe's premier club competition last season by defeating Bayern Munich on penalties in the final, and have picked up four points from two matches in Group E so far this campaign.
"It's a huge ask, but there is obviously a chance because we're in it," he told Sky Sports News. "We've got confidence from last year and we've adapted our style a little bit this year and it's coming together.
"It's a long competition, you have to qualify first then you have to regroup in February if you get that far.
"It's a long road, but we believe at the minute and we'll have to keep working hard to try and get it."