O'Neill assumed temporary charge five weeks ago following Brendan Rodgers' resignation, and the 73-year-old's comeback has resulted in four successive league wins, bringing the team within two points of the leaders Hearts with a match still to play.

Celtic will host Dundee on Wednesday, while Hearts are set to play at home against Kilmarnock, and O'Neill has narrowed the gap to the summit after taking over when the squad was eight points behind the leaders.

Media coverage has linked French coach Wilfried Nancy with the position over the past few weeks, with speculation about when O'Neill would step down. The Northern Irishman confirmed his exit at the pre-match press briefing.

"You can be assured that tomorrow night will definitely be my last game," O'Neill told the press.

"The board has given me their assurance. The new manager will be arriving; I’m not clear on the details of the process, but I know this is certainly my final match."

O'Neill, who secured three league titles and three Scottish Cups during his previous five-year tenure, returned to management briefly after more than six years since his last role, and he accepts the temporary nature of his stint.

"That was the plan from the start, whether it lasted two weeks or five or six weeks," O'Neill explained.

"That was always understood, so I have no complaints whatsoever.

"A young man is coming in now, and it's his responsibility, but we have a crucial game tomorrow evening and naturally, I want to try to win it if possible."

Nancy has built his managerial career in Major League Soccer, beginning with CF Montreal where he succeeded Thierry Henry in 2021 and led the team to victory in the Canadian Championship final before moving on to Columbus Crew.

At Columbus Crew, the 48-year-old has won the MLS Cup and the Leagues Cup, and earned the MLS Coach of the Year award in 2024. If Nancy departs the American club as expected to join Celtic, his first match in charge will be a home fixture against Hearts on Sunday.