Borussia Dortmund have reportedly made Chelsea loanee Ian Maatsen their priority target for the summer transfer window.
Maatsen has established himself as a key player in Edin Terzic's side since he completed a loan move to Signal Iduna Park in January.
The full-back has made 22 appearances in all competitions, contributing to the club's attacking efforts with three goals and two assists.
Maatsen has started all six of Dortmund's Champions League knockout games, helping the German side reach their first Champions League final since 2012-13.
Dortmund prioritising Maatsen transfer
After scoring in Dortmund's 4-0 league win over Darmstadt on Saturday, Maatsen is now preparing for a Champions League showdown with Real Madrid at Wembley on June 1.
While he is currently focused on matters on the pitch, a decision will have to be made on his long-term future ahead of next term.
As it stands, Maatsen will return to his parent club Chelsea when his loan deal concludes at the end of the season.
However, according to journalist Patrick Berger, Dortmund are making it one of their top priorities to sign Maatsen on a permanent deal this summer.
In fact, the Bundesliga club are hoping to make significant progress in negotiations and make the defender their first signing of the summer transfer window.
Dortmund reluctant to meet Maatsen's release clause
Dortmund have already held initial talks with Chelsea and are hoping to bring the price down from Maatsen's reported €35m (£30m) release clause.
Maatsen is believed to be keen to join Dortmund on a permanent basis after failing to establish himself in the Chelsea first team.
The Chelsea academy product spent time on loan with Charlton Athletic, Coventry City and Burnley, before he turned down the chance to join the Clarets in a permanent transfer last summer.
Maatsen was unable to force his way into Mauricio Pochettino's plans, starting just one of his 12 Premier League appearances in the second half of the season.
The switch to Dortmund has ultimately presented him with the chance to enjoy regular playing in one of Europe's top five leagues.
