In the liner notes for the Repertoire re-release of Home, Gary Brooker reminisces about early personnel-changes.
GB: He was a good man, Dave Knights, and he'd always played the bass notes I told him to, so he'd done a great job! But we'd come to a phase where virtuosity in 'live' performances was coming into its own and Robin felt that Dave wasn't quite the man ...
Gary Brooker on other fellow-Procolers
More from Brooker on Knights (search for 'complaints about what David did ')