Chelsea were held to a 1-1 draw by the Belgian champions, having won the first game between the two 5-0.
“The first half was good, we managed to get the goal we wanted, the second half we went down a level, in the first 20 minutes we could have had more control of the game”, he told Sky Sports.
“I think we had fantastic opportunities to win the game but it just didn’t happen, we have to get these opportunities in the back of the net.
“That’s the most important thing in a football game.”