The Croatian winger is currently on loan at Torino and only has a year left on his contract with his parent club Wolfsburg.
Torino had an option to make the move permanent for a fee of €10m, but the deadline for it expired this week and he is now available in the market this summer.
The Italian club have tried to get a discount from Wolfsburg but that has not led anywhere and several other teams are now interested in signing Brekalo.
Southampton have already been linked with a move for him and, according to Italian outlet Calciomercato.it, West Ham are also in the mix.
The Hammers are amongst the clubs who have made enquiries for him and have a concrete interest in signing him.
David Moyes wants to add more attacking thrust to his squad over the summer and Brekalo is one of the players they are considering.
Atletico Madrid and Eintracht Frankfurt are claimed to be keen on signing the Croatian winger this summer.
Wolfsburg are prepared to sell Brekalo but are not willing to accept anything less than €10m for him.
