West Ham have been offered the chance to sign New York Red Bulls centre-back Aaron Long.
The 26-year-old wants to play in the Premier League and has a $5m (£4m) release clause in his Red Bulls contract.
Fiorentina and Lyon want to sign the USA international, who was named 2018 MLS Defender of the Year.
Long has made 11 MLS appearances this season and started five of the USA's six matches during this summer's Gold Cup.
Earlier this week, West Ham completed the signing of striker Sebastien Haller from Eintracht Frankfurt on a five-year deal for a club-record fee.
The Frenchman's arrival has seen West Ham break their transfer record for the third time in a year following the signings of Issa Diop and Felipe Anderson.
Follow the Summer Transfer Window on Sky Sports
Sky Sports News is home to three new shows dedicated to bringing you the very latest news from this summer's transfer market.
Start your day with Good Morning Transfers at 9am as our team of reporters and pundits bring you the latest news and insight. Transfer Talk then follows at midday, delivering the biggest stories that matter to you. And join us at 7pm for the definitive round-up of the day's news with The Transfer Show.
And as well as tuning into Sky Sports News, don't miss a thing with our dedicated Transfer Centre blog.
There's also the Transfer Talk Podcast, the daily UK, Regional and European Paper Talk, plus features across skysports.com and the Sky Sports app.