Borussia Dortmund do not have first option on Ian Maatsen this summer, with Chelsea's £35million release clause open to any clubs interested in the 22-year-old left back.

Maatsen enjoyed an excellent loan in Germany, though endured an unfortunate end to the season in Saturday's Champions League final, playing the erroneous pass which saw Real Madrid score their second goal at Wembley Stadium.

Maatsen had impressed before that mistake and Dortmund, more than pleased with his overall work, want to keep him. 

They are the favourites to secure a permanent transfer, but could yet face competition for the Chelsea loanee, who has been monitored by clubs in the Premier League and La Liga.

The stance of Chelsea's new head coach Enzo Maresca is not yet known, with his appointment set to be confirmed this week, but the current expectation is that Maatsen will be sold this summer.

Borussia Dortmund do not have first option on signing Ian Maatsen permanently this summer

In the Champions League final, Maatsen was helped by Karim Adeyemi, who provided protection up until his substitution in the 72nd minute. 

Jose Mourinho mentioned during his TNT Sport analysis how Real's Rodrygo struggled to secure any one-on-one opportunities with Maatsen due to the cover on Dortmund's left-hand side.

While not excusing the error, Maatsen's mistake came 10 minutes after Adeyemi had been subbed, with some suggesting that it could have been a consequence of tiredness and that it is not a lapse in concentration usually associated with the left back.

That one moment should not overshadow an otherwise impressive season from Maatsen, who was a regular starter in Dortmund's line-up after joining on loan in January.