Manchester United will not let Diogo Dalot leave in January unless a replacement is first found.

Dalot is being linked with a move to AS Roma in the New Year and United are reportedly happy to let him go - but only on one condition.

Sky Italia's Gianluca Di Marzio says former manager Jose Mourinho will be able to sign his top target only if United manage to secure a replacement - ideally Kieran Trippier.

The Atletico Madrid fullback was a target for United last summer, before and after the Euros.

Dalot, meanwhile, spent last season on-loan in Italy with AC Milan.