Alex McLeish has emerged as the frontrunner to take over at Scottish Premiership side Rangers.
Warburton subsequently claimed that he had not resigned, but Rangers insisted that the former Brentford boss had tendered his resignation in order to pursue an opportunity at another club, thought to be Nottingham Forest, before attempting to change his mind.
According to the Daily Mail, Gers are now thought to be interested in appointing McLeish on a short-term contract running to the end of the season before hunting for a long-term successor in the summer.
McLeish previously managed Rangers between 2001 and 2006 and guided the club to two league titles, two Scottish Cups and one Scottish League Cup.
Rangers are currently third in the Scottish Premiership table, 27 points behind leaders Celtic.