Manchester City's Aymeric Laporte could be on his way Barcelona, Spain's Mundo Deportivo reports.
The 25-year-old defender is under contract for 2025, but Barca - keen for another central defender - hope he will ask for a transfer due to City's Champions League ban.
Manchester City, meanwhile, could be eyeing a likely replacement for Laporte in the form of Milan Skriniar, according to Italy's Calciomercato.
The Inter Milan and Slovakia defender has had only a moderate season, but is said to have been unsuited by Inter's three-man defence. City would face competition from Real Madrid and Paris St Germain for his signature.
Manchester United could be poised to swoop for Napoli centre-back Kalidou Koulibaly, the Daily Mirror says. The 28-year-old is reportedly keen to leave Napoli, and United are said to be first in line to acquire the Senegalese star.
Arsenal and Liverpool are in the market for Eintracht Frankfurt's Evan Ndicka, according to Sky Sports.
The 20-year-old French defender was being monitored by both clubs before the season was suspended due to coronavirus. Valencia, Sevilla and both Milan clubs are also keen on the left-footed centre-back.
Antoine Griezmann could be suddenly on the market, Spanish website Sport reports. France's 2018 World Cup hero only joined Barcelona last summer from Atletico Madrid in a deal worth €120million, but the Catalan club would be willing to sell him at a loss.
Not only has Griezman not performed to expectations this season, Barca are looking to save money as the coronavirus crisis hits football.