Chelsea players are worried for their futures at the club after sanctions were imposed on owner Roman Abramovich due to his links with Russian president Vladimir Putin.
As many as nine out of contract players, including Cesar Azpilicueta, Antonio Rudiger and Andreas Christensen, could walk away from the club in the summer.
Atletico Madrid manager Diego Simeone could look to sign Chelsea striker Romelu Lukaku following a sustained run of poor form.
The ownership of Paris Saint-Germain want to get rid of mercurial attacker Neymar following the club's surrender in the last 16 of the Champions League against Real Madrid. Meanwhile, the PSG hierarchy wants to keep Real target Kylian Mbappe at all costs.
Scouts from Manchester United were sent to watch Lyon striker Moussa Dembele in action against Porto in the Europa League. The Red Devils are pondering a £25m move for the Frenchman with Edinson Cavani and Cristiano Ronaldo's futures uncertain.
In that same game, Liverpool sent scouts of their own to watch Porto - the club they signed Luis Diaz from in January.
United are yet to make a new contract offer to midfielder Paul Pogba, who could wait until his current deal expires in the summer before making a final decision about his future. Real Madrid are interested.
Liverpool have made contact with Villarreal over impressive teenaged winger Yeremy Pino, who is already a full Spain international at 19. The Reds could face competition from Man City for a player who has an €80m (£67m) release clause in his contract.
Atletico Mineiro winger Savinho, aged just 17, will join Manchester City in the summer after a transfer was agreed for €6.5m plus add-ons.
Arsenal could target as many as six new signings in the summer, despite their mini-overhaul across the past two transfer windows. Crystal Palace winger Michael Olise is one player attracting interest from the Eagles' north London rivals, with Lille's Jonathan David also identified as a key target.
Fiorentina hope to tie up a permanent deal for forgotten Arsenal midfielder Lucas Torreira, who is currently at the Italian club on loan.
Barcelona will allow goalkeeper Neto to leave in the summer and are planning ahead with Inaki Pena, who impressed against his parent club in the Europa League on Thursday night.
Aston Villa manager Steven Gerrard has suggested it will be difficult for the club to sign Philippe Coutinho on a permanent basis from Barcelona. Villa have the option to sign the Brazilian midfielder in the summer for £40m.
Source : 90min