An initial £85m inquiry from United for central defender Koulibaly was rejected last week by the Serie A club.
That came with a warning they will not listen to offers of less than £150m. The Italians confirmed the hands-off stance by turning down £90m from Real Madrid on Friday.
All of which seems to have done the trick in deterring United from their pursuit of Koulibaly – for now at least.
Instead, the fallen Premier League giants' focus is firmly back on fast-rising Portuguese international Dias.