Inter, Everton and Brighton are watching Sassuolo's Jeremie Boga, but Napoli’s interest remains the most concrete after the former Chelsea man hit his best form in Serie A.
Napoli have already made a first offer of €20 million (£17m/$22m) for the 23-year-old and have put a €1.5m-per-season contract on the table.
However, having so far failed to get an agreement in place, Napoli could face competition from a Serie A rival and clubs in the Premier League.
Inter are looking at signing a forward and Boga has trained under Antonio Conte but their interest depends on any future outgoings with Romelu Lukaku and Lautaro Martinez currently operating in a front two.
Conte gave Boga his solitary Chelsea appearance after he impressed in the Blues’ pre-season campaign in 2017, but he was hauled off after a red card for Gary Cahill on his debut against Burnley.
Everton may want to refresh their forward line in the summer with the futures of Cenk Tosun, Theo Walcott, Oumar Niasse and, to a lesser extent, Moise Kean uncertain as Carlo Ancelotti bids to turn the Toffees’ fortunes around.
Boga has four goals and an assist in his 18 games this season during Sassuolo coach Roberto De Zerbi's mission to steer clear of relegation and look upwards in the table.
The Ivory Coast international has represented good business for the Italian club after they signed Boga in a €4m deal in 2018 after a host of loan moves during his time at Chelsea.
Boga lined up with the likes of Ruben Loftus-Cheek, Tammy Abraham and Fikayo Tomori in Chelsea's academy but ultimately looked for a move away from the club.
Chelsea hold a €15m (£12.5m/$16.5m) buyback clause that can be exercised at any time, but Boga is likely to cost other clubs somewhere in the region of €23m (£20m/$26m).
But, despite having their option to sign Boga, the Blues are not yet thought to be considering a move for their former player, even though Frank Lampard’s side are looking for a striker or winger after having their transfer ban lifted ahead of the January window.
Barcelona have been linked with signing Boga in recent weeks but he is a long way down their priority list with Dinamo's Dani Olmo their main January target.
Paris Saint-Germain's Neymar continues to be a long-term target at Camp Nou so any move for the Sassuolo forward looks unlikely.