Since Brendan Rodgers resigned as Celtic manager on Monday, several candidates have emerged as the Northern Irishman's long-term successor. Celtic moved quickly to appoint former manager Martin O'Neill as interim boss - 20 years after his first stint in charge of the Glasgow club ended. Sunday's 3-1 defeat at table-toppers Hearts was Celtic's second successive Premiership loss, leaving them eight points adrift in second place, while they have won just two of their last seven matches across all