Hogan has battled back from career-threatening injuries to become one of the hottest strikers outside of the Premier League and Brentford are facing a battle to keep him.
The Irishman spent two years on the sidelines after suffering two anterior cruciate ligament injuries to the same knee, but returned at the end of last season and immediately hit the goal trail.
The 24-year-old has also fired home 14 goals this campaign and it is no surprise the likes of Newcastle and Reading have been linked with mammoth bids.
West Ham have also entered the running, with some reports claiming they have already had one bid of £7million rejected as the Championship outfit hold out for £10million.
Brentford will be reluctant to sell this month but will struggle to turn down that kind of figure if West Ham raise their offer.