Chelsea are understood to have made a £112million offer to Benfica for Enzo Fernandez.
Portuguese sources say the proposal is above the midfielder's £106m buy out clause but would be paid in three instalments of £37.3m over three years.
The format is similar to the deal constructed by Atletico Madrid to buy Joao Felix from Benfica in 2019.
Benfica have reiterated they wish to keep Fernandez but the 21-year old, who returned to Argentina at the weekend, is eager to make the move.
Further negotiations will take place later today as the Portuguese side decide whether to accept the structure of Chelsea's offer.