After Green left Fleetwood Mac in 1970, he worked with Watson on two solo singles, "Heavy Heart" and "Beasts of Burden", the latter being credited to both musicians. Watson also accompanied Green as conga player on a tour of the United States with Fleetwood Mac in February 1971. Jeremy Spencer had suddenly left the band and they asked Green to fill in and help them fulfil their tour obligations. Watson was at that time the brother-in-law of Fleetwood Mac's manager Clifford Davis.
In 1996, Watson and Green started working together again, and Watson was influential in persuading Green to return to music after he had been musically idle for several years. They formed the Peter Green Splinter Group, and released several albums over the following few years until the group split in 2004. Green was not always comfortable taking centre-stage when playing live, and Watson provided an extra focus onstage, singing as well as playing lead guitar. He also composed many songs recorded for the albums.