Potter felt the performance was a big positive for his side despite the 1-0 scoreline in favour of Borussia Dortmund.
He told BT Sport: “You always need a bit of luck but you can’t wait around for luck to come your way. You need to keep working, which is what the team are doing.
“The boys have been fantastic. At the moment we are suffering in terms of results but the performance was a big step forward.”
The Chelsea boss also felt his side were unfortunate not to get something from the game.
“It was a very strong performance from us, especially in the second half. Overall, we created a lot of chances, had a lot of efforts on goal.
“Of course we’re disappointed with the goal we conceded but I thought we were the dominant team in the second half. We need to regroup and attack the game at Stamford Bridge.”
READ MORE: Dortmund 1-0 Chelsea: No way through for frustrated Blues as Dortmund take lead into second leg
