Alexis Sanchez reportedly received bonuses totalling £5m in 2018 as part of his contract at Manchester United.
The Chilean forward completed a move to Old Trafford in January in a deal which saw Henrikh Mkhitaryan move to Arsenal.
It is thought that Sanchez's contract at United saw him earn a weekly wage of £400,000 a week, making him the club's highest earner.
According to The Sun, the forward accumulated £5m in bonuses over his opening 12 months in Manchester, during which he only managed to score five goals.
It is claimed that Sanchez, now on loan at Inter Milan, earned around £31m for making 45 appearances at Old Trafford.
The 30-year-old is said to have no intentions of returning to United after his season-long loan ends at Inter following what he described as the 'worst' period of his career.