Watford are eager to close a permanent deal for M'Baye Niang.
The Daily Star says as part of the loan deal that took the AC Milan star to Watford last month, Walter Mazzarri will have to pay a club record £13.5m if Niang scores 10 goals.
Niang is already off the mark after scoring and starring on his home debut in Saturday's 2-1 win over Burnley.
And it's believed a deal is already in place to take the Frenchman from the Serie A club in a permanent move.
Watford fear Niang - who attracted strong interest from West Ham before joining Watford - will be targeted by their Premier League rivals.
It has prompted them to insert a clause where they have first refusal on any deal to leave them in the box seat to seal his signature.