Mawson played every game of Swansea's 2017/18 season, which saw the Welsh club relegated from the Premier League. Whilst the club endured a poor campaign, Mawson's performances in defence earned him plenty of admirers, and it's understood West Ham are well placed to sign the young Englishman.
A report in The Times claims that West Ham have given new manager Manuel Pellegrini the green light to pursue Mawson for a fee somewhere in the region of £20m, although it's understood Swansea have been holding out for more.
Pellegrini is keen to rebuild a West Ham defence that conceded a Premier League high 68 goals in the 2017/18 season, and the signing of Mawson would certainly help in that department. The Hammers are also keen on a deal for Mawson's teammate Lukasz Fabianski, with an announcement reportedly imminent.
West Ham fans will also be encouraged by the growing rumours of Mawson's arrival, given Hammers fans have frequently displayed their displeasure at the lack of quality investment in their playing squad. Mawson's Premier League experience and potential to become a top centre back should ease some of those fears.
Whilst Swansea fans will be understandably disappointed at losing one of their top players, the £20m fee should soften the blow and give the club's new manager Graham Potter the chance to recruit wisely as the Swans look to return to the top flight.