If Denis Suarez features against former side Manchester City in the Champions League on Wednesday then Barcelona will have to pay the Premier League club an additional €800,000 for the midfielder, according to reports.
Despite Suarez leaving Barca for Villarreal on a permanent basis in 2015, following a loan spell with Sevilla, the original terms of the 2013 deal which took him to Camp Nou still stand.
The Catalan club paid City €1.6 million to sign the 22-year-old for their B team three years ago.
AS and Mundo Deportivo report that several clauses were written into that transfer: a further €800,000 if and when he became part of the first team and then an additional €800,000 for each 10 official matches he plays up until his 100th appearance -- so a potential €8.8m on top of the initial €1.6m.
Suarez, in his first season with Luis Enrique's first team, has played nine games so far -- seven in the league and two in the Super Cup win over Sevilla.
Therefore, when he makes his next appearance, which coincidentally could be against City this week, Barca will have to pay the English club the first of what could end up being 10 €800,000 instalments.
Barca spokesman Josep Vives confirmed that the clauses still stand when the Blaugrana re-signed the player from Villarreal for €3.25m in the summer.
In total, Suarez, if he goes on to feature 100 times or more for Barca, could end up costing €13.65m.
He's unlikely to start against Pep Guardiola's side, though, with Sergio Busquets, Andres Iniesta and Ivan Rakitic still Enrique's preferred midfield trio for the big games.
However, he has been one of his manager's go-to players off the bench, coming on as a substitute in each of the last four La Liga games.