Celtic announced on their official website on Sunday that manager Brendan Rodgers had resigned and left the club effective immediately.

Celtic did not elaborate on the reasons for Rodgers' sudden departure in their official statement, only wishing him well in the future.

However, according to an exclusive report from The Athletic, Rodgers had actually been having serious disagreements with the management this summer regarding transfer policies, philosophies, and budgetary matters.

With the Bhoys' recent decline in performances, the conflict between the both sides escalated sharply, culminating in Rodgers' resignation this week.

Unlike typical management staff changes, all members of the coaching staff, including assistant coach Sean Maloney, have chosen to remain with the club.

This will be the second time Rodgers has left Celtic mid-season.

Meanwhile, veteran Northern Irish manager Martin O'Neill who managed the club from 2000 to 2005, has agreed to return immediately as interim manager.

O'Neill has completed his managerial debut back at Celtic Park, securing a comfortable 4-0 victory over Falkirk.

This will also be O'Neill's first managerial role since being sacked from Nottingham Forest four years ago.

In an interview with Celtic's official website after completing his appointment procedures, O'Neill said: "I'm really excited. Both nervous and excited. Of course, I want to do my best, and I'm looking forward to it."

"The club is looking for a permanent manager, and I've been temporarily called up as head coach, and that will continue."

"Returning to the bench makes me both nervous and excited, and of course, I'm eager to win games; that's the most important thing."

"We have a few key players injured, but the team as a whole is strong. Perhaps we're not used to losing, so we might have lost some confidence because of that." "I'm worried, but the players are all very good players, and I really look forward to working with them."

"We have some very good players who have won games, and it feels great to walk into the dressing room with players who have won games."

"They know how to win, so the most important thing now is to rediscover that feeling, and that's the most important message I want to convey."

About Brendan Rodgers

Rodgers, 52, was born on January 26, 1973, in Carnlough, Northern Ireland. He is 1.7 meters tall and previously played for Reading, but was forced to retire early at the age of 20 due to a serious leg injury.

After retiring, Rodgers joined Chelsea as reserve team manager in the summer of 2006 at the invitation of Portuguese head coach José Mourinho. He left two years later to become Watford manager, helping the club avoid relegation.

In June 2009, Rodgers returned to Reading as manager, but was sacked in mid-December due to poor results.

In July 2010, Rodgers became the manager of Swansea City, successfully leading the team to win the Championship play-offs and earning much praise for his dazzling attacking football style.

In July 2012, Rodgers replaced Liverpool legendary player and manager Kenny Dalglish as the team's manager.

During his three-and-a-half-year spell at Liverpool, Rodgers was praised for successfully developing the potential of players such as Daniel Sturridge, Philippe Coutinho, Luis Suarez, and Raheem Sterling. However, after Suarez's move to Barcelona in 2014, Rodgers was unable to adequately fill the void left by the Uruguayan legend in the attack, leading to his dismissal in October 2015.

The following May, Rodgers was appointed as Celtic manager for the first time.

During his two-and-a-half-year spell managing Celtic, he won two Scottish Premiership titles, two Scottish Cup titles, and three Scottish League Cup titles.

In February 2019, Rodgers returned to the Premier League as manager of Leicester City.

During his time there, he won the Community Shield and the FA Cup, but due to the club's financial difficulties and poor performances, he was sacked in early April of 2023.

In the summer of 2023, Rodgers returned to Celtic as manager.

In the past two years, Rodgers has won two Scottish Premiership titles, two Scottish League Cup titles, and one Scottish Cup title with the club.