The Chelsea midfielder arrived in Dortmund during the January market on-loan to the end of the season. However, the England U21 international has been used sparingly by Kovac so far. "He played little in London," said Kovac. "We have to build him up selectively.

Borussia Dortmund coach Niko Kovac was delighted with his team's 2-1 comeback victory at Lille in the Champions League on Wednesday but predicted they would need to lift their game further to see off Barcelona in the quarter-finals.

Niko Kovac accepts Barcelona will be a step up in quality compared to Lille when the sides meet in the Champions League quarter-finals.

Borussia Dortmund coach Niko Kovac says he was “very clear and direct” with his players in a meeting to address yet another Bundesliga loss ahead of the second leg against Lille in the Champions League round of 16.

Borussia Dortmund goalkeeper Gregor Kobel lets the ball in through his legs from a shot by Lille forward Jonathan David in the second leg of their Champions League last-16 tie.

Borussia Dortmund coach Niko Kovac said on Tuesday he had been trying to sharpen his players' senses ahead of Wednesday's Champions League Round of 16 return leg against Lille, after the Ruhr valley club suffered a Bundesliga loss on Saturday.