Mangotsfield United were due to play Chipping Sodbury Town in the Gloucestershire Football Association Challenge Cup on Tuesday night but the game was postponed as a result of a waterlogged pitch. The match was later conceded meaning that the eight-tier club had to withdraw from the competition.
Bater, who played for Cardiff City and Wrexham in his career, oversaw a key win over Tuffley Rovers, but suffered heavy defeats to Clevedon Town in the FA Vase and to Worcester Raiders in the league.
The club's board however has confirmed that Bater, after just three games in charge at Cossham Street, is leaving, and is a decision taken by the 67-year-old, not the club themselves. They have described his exit as 'unexpected' and 'completely sudden' and expressed their disappointment given they felt he was the right manager to lead the club to survival.
A statement published on their social media feed on Tuesday evening read: "The club can officially announce the unexpected departure of Phil Bater as manager. This is not a decision made by the club & was completely sudden & unexpected. The club believed that Phil was the right manager to move the team forward & is disappointed that he’s decided not to continue.
"To organise the management of the team at such short notice would have been impossible for tonight’s game, so we took the decision to postpone the cup game (which then had to be conceded) and use the time to speak to our players individually and organise our squad ahead of training and resumption of our league programme this Saturday.
"The club already has an interim management team in place and a squad committed to doing their best for the club. We move forward as one club on and off the field."
At the time of his departure, Mangotsfield United are 17th, a point ahead of the relegation zone, though Tuffley and Thornbury Town have a game in hand over the north-east Bristol club. Mangotsfield's next match is against Brimscombe & Thrupp, which is the first game of the interim management's tenure. Brimscombe & Thrupp are currently 14th, three places higher and seven points ahead of Mangotsfield.