The Blues have asked for conditions on signing the forwards, having attempted a swap deal to sign Aston Villa's Jhon Duran and seeing a £34m bid rejected for Atletico Madrid's Samu Omorodion.
David, 24, who is currently playing in the Copa America with Canada, has been subject to early talks and would cost less than £30m as he enters the last year of his deal at Lille.Chelsea are also interested in Guiu, 18, whose deal at Barcelona expires next summer and has a £5m active release clause in it.
Guiu, who has scored twice in six appearances for Barcelona, is also in talks to renew his deal with the Catalan giants.Strange cases break out in a remote Welsh villageHometown hero Jordan takes England to 'crunch time' in Barbados'A kick to the Turkey teeth!' - Akaydin scores incredible own goal. VideoFleeing Kabul, chasing gold - the story of a refugee Olympian