Niko Kovac knows his Borussia Dortmund side remain a work in progress but he sees signs of improvement ahead of their Champions League last-16 tie against Lille.

Kovac, a former Bundesliga champion with Bayern Munich, took charge of Dortmund at the end of January following the dismissal of Nuri Sahin.

He guided BVB past Sporting CP in the Champions League play-off round, with their reward being a round-of-16 meeting with Lille, who they host in the first leg on Tuesday.

Dortmund have only lost one of their last 16 home matches in the Champions League (10 wins, five draws), with that lone defeat coming against Barcelona last December (2-3). 

They are also unbeaten in their last five home games in the knockout stages of the competition (four wins, one draw), having gone all the way to the final last term.

Dortmund are languishing in 10th place in the Bundesliga and are at risk of missing out on European qualification for next season, but Kovac is enjoying the challenge of reviving them.

"We have become more settled, we work hard every day on the training ground and in the meeting room. We are still far from where we want to be. But the way the boys are going along with it pleases me," Kovac told reporters.

He added that Lille will be formidable opponents, saying: "They play a very versatile brand of football. This will demand a lot of strength and concentration from us.

"They didn't make it into the top eight for nothing and have, for example, beaten Real Madrid. It's going to be a tough nut to crack."

The two teams have only met once before in European competition, with Dortmund winning on away goals in a two-legged UEFA Cup last-16 tie in 2002.

Given Dortmund's strong home record in Europe, Kovac believes the passionate support they receive at the Westfalenstadion could be a key advantage for his team.

He said: "Our stadium, it's a big castle. It's tough to play here – very tricky and very hard. I hope we can use the atmosphere to make an impression on Lille."