Wigan Athletic are in hot pursuit of Sunderland defender Zak Johnson, with the 21-year-old's contract set to expire at the end of the month. Johnson spent last season on loan with York City, playing a key role in their National League title success. However, Sunderland are expected to let him leave this summer, and Wigan Athletic are confident of luring him to the League One club. Oxford United are also showing interest in Johnson, but Wigan Athletic hope to build on their mid-table finish last season. Zak Johnson's impressive performances on loan have placed a number of EFL sides on alert, with the centre-back likely to be available as a free agent. Regis Le Bris, the Sunderland manager, is planning ahead for next season, and Johnson is not expected to play a part in the Black Cats' plans. Wigan Athletic's interest in Johnson is a sign of their ambition to improve their squad, and the club will be hoping to secure his signature in the coming weeks. The transfer window is set to be busy for Wigan Athletic, as they look to strengthen their team and push for a higher finish in the League One table.