Former Manchester United boss Sir Alex Ferguson's earning capacity hasn't dropped since he left the job.
The Daily Mail say Ferguson, 73, was paid an advance of £2m for his second autobiography published later that year.
It became the biggest-selling book of 2013, with sales earning him at least an additional £1m.
Ferguson continues to bank more than £2m a year for 20 appearances as a club ambassador for United, a role that was agreed when he stepped down as manager.
Industry insiders estimate that he is able to command a fee of up to £100,000 a day for public speaking engagements, with his son Jason understood to be negotiating all business dealings on his behalf.