Norwich sacked Manning after just 158 days in post after joining from Championship rivals Bristol City in the summer, winning just two of his 15 league games in charge of the club.
His dismissal was confirmed hours after the club’s 2-1 defeat to Leicester at Carrow Road on Saturday afternoon, their eighth successive home loss to start the season. That news began the hunt for their sixth boss in just shy of four years, with under-fire sporting director Ben Knapper expected to lead the search for Manning’s successor.
O’Neil, most recently head coach of Wolves, turned down an opportunity to return to Molineux last week, but leads the betting market to succeed Manning in the hours after his exit was confirmed.
Former Liverpool and Celtic boss Brendan Rodgers is the second favourite after resigning as boss of the Scottish champions last month. City legend Martin, who was sacked 17 games into his reign at Rangers, and ex-Middlesbrough head coach Michael Carrick complete the top four at this early stage.
Supporters are also monitoring events at Leeds United after legendary managerial figure Daniel Farke’s future was plunged into doubt with a 3-1 defeat to Nottingham Forest on Sunday.
First-team coach Ryan Garry has been placed in interim charge and will be assisted by goalkeeper coach Tony Roberts and set-piece coach Nick Stanley.