Manchester United could approach Fiorentina to sign defender Nikola Milenkovic in January, according to Sky in Italy.
The 21-year-old has started in all 12 of Fiorentina's Serie A games this season, scoring two goals and retaining his place in the Serbia national team after playing in last summer's World Cup.
Sky in Italy understands Jose Mourinho is interested in signing Milenkovic in January or in June as he looks to strengthen his United back-line which has conceded 21 goals in 12 Premier League games this campaign.
However, Fiorentina chairman Mario Cognigni stated in September that the club turned down a £36m offer for the player in the summer.
This means the Serie A club could be expecting potential suitors to fork out at least £50m for the Serb, who has also attracted attention from Chelsea, Arsenal and Juventus.
Milenkovic, a 6ft 5in centre-back who can also play at right-back, was originally signed by Fiorentina from Partizan Belgrade in 2017 for a fee of around £4.5m, and has a contract running until June 2022.
Sky in Italy understands that United could also target Sampdoria's 22-year-old Joachim Andersen should their move for the Milenkovic fall through.
The Denmark international defender has impressed since the beginning of the season, featuring in all 12 of the Italian side's league games so far.
Inter Milan and Juventus are also interested in Andersen and have already made contact with Sampdoria over a potential move in January.