Sources: Martin O'Neill makes Celtic formation decision ahead of Motherwell clash

Celtic are likely to revert back to their usual back four shape against Motherwell on Sunday, sources have told Football Insider.

Martin O'Neill opted to switch to a back three system for the defeat to Rangers before the international break, but it is understood that was merely a ploy to try and match up with their rivals' shape.

However, O'Neill is not planning to stick with that setup when the Scottish Premiership returns to action next weekend.

Sources say that the addition of a new centre-back is also not a top priority for Celtic in January, with O'Neill satisfied with the depth if the team play a back four.

The Bhoys have just four senior centre-backs in their squad, but it has already been decided that a new addition in that area is not necessarily needed.

Celtic return to league action away at Motherwell, but O'Neill and the team are under huge scrutiny after a difficult spell in recent weeks.

Celtic squad looking to rebuild confidence

Celtic suffered some damaging defeats before the international break, but they will be desperate to get back on track at Motherwell this weekend.

O'Neill's men were beaten twice by Rangers without scoring, with that pair of losses sandwiched either side of a home loss to Ferencvaros in the Europa League.

Football Insider revealed at the end of September that Celtic have been dealt a blow of "psychological damage" by those three results.

The squad have had their confidence dented badly, and they also find themselves under ever-increasing pressure from supporters.

However, O'Neill has no plans to make any major changes to the style of play, and is ready to revert back to the 4-2-3-1 that has previously brought success for his team.

Celtic could 'explode' after club take 'huge risk'

Former Manchester United chief scout Mick Brown told Football Insider on Monday that Celtic could potentially "explode" after the latest scathing statement from their board.

Fans protested against owner Dermot Desmond while he played golf at the recent Alfred Dunhill Links Championship, and the board have responded by cutting into their own supporters.

Brown is adamant that the Celtic hierarchy may have just turned a "volatile atmosphere" into a "toxic" one, and have not helped anything with their statement.

Desmond cuts a hugely unpopular figure at Parkhead at the moment, and things could potentially come to a head in the coming weeks.