Jules Kounde, a France international, was on the verge of joining Chelsea this summer before deciding to join Barcelona instead.
According to Relevo, Kounde chose not to sign with Chelsea because of the position former Chelsea manager Thomas Tuchel wanted him to play in.
According to the report, Chelsea were close to signing Kounde from Sevilla until Thomas Tuchel informed him that he would be used as a right wing-back in a back five.
Kounde was dissatisfied with how Tuchel planned to use him at Chelsea and decided against moving to Stamford Bridge.
Tuchel wanted to play Kounde as a right wing-back, but Barcelona manager Xavi Hernandez reportedly promised the France international that he would play as a centre-back alongside Ronald Arajo.
Barcelona signed Kounde for £47 million, one of several high-profile signings.
If Tuchel had offered to play Kounde as a centre-back in his back three rather than a right wing-back, the France international might still be a Chelsea player today.