Middlesbrough have reportedly signalled their intention to try to sign Chelsea defender Tomas Kalas on another loan deal.
Kalas has spent the last 18 months at the Riverside Stadium, making a total of 43 appearances in the Championship to help Middlesbrough secure a return to the Premier League.
The Czech Republic international has since returned to Stamford Bridge but after reports linked him with a third switch to the North-East, his agent has confirmed Boro's interest.
Mithat Halis is quoted by Gazette Live as saying: "Kalas wants to stay in England next season, preferably in the Premier League. He is happy at Chelsea but Middlesbrough are interested."
Kalas has only made two starts during his time at Chelsea, both of which came at the end of the 2013-14 season.