Chelsea boss Enzo Maresca admits he's unsure of what to expect from FC Copenhagen tonight.

Chelsea host the second-leg of their round of 16 Europa Conference League tie leading 2-1 on aggregate.

Maresca said afterwards: "I was surprised, as I said last week because I watched many games, they were off the ball always defending with a line of four and then against us, they were in a line of five. Even in their game two days ago, they were again a line of four. The reason why we were a little bit surprised was because of that, but then we tried to adapt.

"Tomorrow, to be honest, I do not know if they are going to be in one way or another way. We will see tomorrow.

"Tomorrow, for sure, will be a different game. I watched the game but I don't think it has anything for tomorrow's game. We watched the game to see how they behave but I watched many games before the first-leg and they changed completely against us, so we will see tomorrow."

Asked if he felt the players are now playing his style of football, Maresca admits he can see progress.

"I think football always evolves but then you can find teams in the league that just play one way or a team that plays in different ways. We have 20 clubs in the Premier League and more or less we are all different.

"Teams try to be aggressive with high pressing and some prefer to sit back and go with transition. I think it is clear we try to be aggressive off the ball and try to control the game on the ball, score when we need to score and defend when we need to defend.

"In this moment, I think we are the second or third best attacking team in the Premier League, so that means we are scoring lots of goals and defending, we are also there but for sure, we can attack better and we can defend better."

Meanwhile, Maresca also revealed attacking players Nicolas Jackson and Noni Madueke will be returning later this month from injury.

"He (Jackson) could be back, probably after the international break. Him and Noni also. This is good news. Before the international break, we have two games tomorrow and Sunday and then we have international break."