Napoli defender Kalidou Koulibaly has reportedly emerged as a transfer target for Manchester United.
Koulibaly has established himself as one of the key men at the Serie A giants, and the Senegal international was recently handed a new contract by the Italian side.
However, that has allegedly not stopped Barcelona eyeing the signing of the 27-year-old, and according to The Sunday Times, United are ready to join the Spanish club in the race for the centre-back's signature.
United boss Jose Mourinho was unable to make an addition in that area during the summer, but the Portuguese is said to have reiterated his desire to strengthen in the middle of his backline.
The North-West giants currently sit in 10th place in the Premier League table, and have conceded 16 goals from their nine matches in the top flight.
Napoli are unlikely to give much consideration to parting ways with Koulibaly midway through the season unless any interested club are willing to pay over his valuation.