Sunderland have expressed an interest in taking Chelsea’s Kurt Zouma on a season-long loan, and they are hoping their sporting director, Lee Congerton’s, close connections with Chelsea will help smooth a deal.

The 19-year-old centre-half, who signed for Chelsea in January for around £12m, remained at his former club Saint-Etienne for the remainder of last season but had hoped to play in the first team at Stamford Bridge next season.

Chelsea have already allowed the young Czech defender Tomas Kalas to join Cologne on a season-long loan. John Terry has signed a one-year-deal and Zoma’s openings may be limited. Gary Cahill and Branislav Ivanovic are also available

The Lyon-born France under-21 international impressed last year at St-Etienne – despite a 10-match ban mid-season for a challenge on Sochaux’s Thomas Guebert – and has the physique to flourish in the Premier League.

Chelsea retain an interest in the Real Madrid centre-back Raphaël Varane.

Congerton, initially appointed as a youth-team coach during José Mourinho’s first spell at Chelsea, worked as chief scout at Stamford Bridge before moving on to Hamburg with Frank Arnesen, and was appointed at the Stadium of Light in March. He has already signed Billy Jones, Jordi Gómez and Costel Pantilimon on free transfers this summer, and secured Sebastian Larsson on a new three-year deal at Sunderland.