The Reds have Swansea's Wilfried Bony and Ryan Bertrand of Chelsea in their sights, while Arsenal have been linked with Loic Remy
Swansea live updates
Sunderland boss Gus Poyet is hoping to add Ashley Williams to his squad after tabling a bid for the defender.
Press Association Sport understands thee Black Cats have made Swansea an offer in the region of £4million for the 29-year-old, who is yet to agree a new deal at the Liberty Stadium.
Williams has a year left on his current contract, and could leave for free next summer.
Poyet is currently reshaping the squad at the Stadium of Light with West Brom defender Billy Jones and Wigan midfielder Jordi Gomez already on board following the departures of Phil Bardsley and Craig Gardner.
In addition, Sebastian Larsson has agreed a new three-year contract, although fellow midfielder Jack Colback's future remains uncertain with derby rivals Newcastle among his suitors.
Leon Britton has signed a one-year contract extension at Swansea.
The midfielder had two years left to run but has now had another 12 months tagged on.
The 31-year-old has made 467 appearances for the Swans since signing for them in 2002, with his only break coming with a brief spell at Sheffield United.