According to Portuguese newspaper Ball, Liverpool will pay an additional transfer fee to Benfica after Nunez started against Burnley.
Nunez scored against Burnley to end a 12-game goal drought at Liverpool.
According to Ball, Liverpool will pay an additional €5 million as part of the original terms of bringing in Nunez from Benfica, a performance-linked add-on.
Liverpool's signing of Nunez is set for a fixed fee of €75 million, with an additional €25 million bonus clause linked to appearances and results.
Liverpool have already paid a variable fee of €5 million as Nunez has made 10 starts in the Premier League and Champions League, while the next €5 million comes after Burnley, as Nunez has made 35 starts in the Premier League and Champions League.
The report claims that if Nunez makes 60 starts in the Premier League and Champions League, Liverpool will continue to pay Benfica 5 million euros, with a further 5 million euros to be triggered if Liverpool win the Premier League or Champions League.