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.
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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.