Plettenberg stated that "final details still need to be sorted out" and confirmed that Kylián Mbappé will remain the highest-paid player in the squad under any new arrangement.
The Brazilian would receive a substantial salary increase under the deal, which is expected to run until 2030.
However, journalist Ramón Álvarez de Mon contradicted the report within hours, saying there is "distance" between the parties on economic terms and that no breakthrough had occurred.
Vinícius joined Real Madrid from Flamengo in 2018 and has made 374 appearances for the club, scoring 124 goals and providing 100 assists. His current contract expires in June 2027, meaning this summer represents the final realistic window to tie him down before the deal enters its final year.
It has been reported that Real Madrid will not include a signing bonus, with Florentino Pérez unwilling to set a precedent. An announcement is expected before the World Cup in June if a deal is concluded.