According to Sky Sports News, the 20-year-old failed part of his Sunderland medical, which took place over the last 24 hours, and additional tests are now required.
Advertisement
Advertisement
Sunderland had agreed a £25.7m deal on Sunday to sign Methalie from Toulouse, beating off some serious competition for his services.
It’s understood the left-back will now return to France and await what happens next with the deal now on the verge of collapsing.
Methalie became a first-team regular for the French club last season having come through the youth ranks, making 31 appearances across all competitions.