Andre Ayew celebrates after scoring for Swansea
Ayew, 26, joined Swansea on a free transfer from Marseille last summer, and lived up to his billing of a marquee signing with a superb debut Premier League campaign.
Liverpool's Dejan Lovren in action with Swansea's Andre Ayew
The Ghanaian hit 12 goals and two assists in the Premier League for Swansea last season, impressing for the Swans whether playing out wide or up front.
Andre Ayew celebrates scoring for Swansea
Slaven Bilic has hit a brick wall in his attempts to sign a new forward this summer, but is now moving to try and sign Ayew - but Swansea may need some time before sanctioning a deal.
It's claimed that Swansea have yet to answer West Ham, and want to bring in another attacker before considering allowing Ayew to make the move to East London.
Manchester City's Nicolas Otamendi in action with Swansea's Andre Ayew
Swansea have seen Eder, Bafetimbi Gomis and Alberto Paloschi all leave the club this summer, meaning manager Francesco Guidolin has no recognised strikers at his disposal, though Ayew can play there if needed.
It's therefore understandable that Swansea would want to bring in at least one forward before letting Ayew leave, but the £20m offer will certainly be appealing given that signed him for nothing just over a year ago, representing a huge profit.
Do you think Ayew is worth £20m?