However, Emery's future will only be decided based on what happens in the Champions League.

PSG face a tough start to 2018 with seven of their first nine matches away from home and one of those is the round-of-16 first-leg clash with Real Madrid at Santiago Bernabeu.

Emery has known since his arrival that higher priority is placed on Champions League success than any form of domestic triumph and the pressure on the former Sevilla boss has increased recently.

According to the source, last season's capitulation to Barcelona and the expensive acquisitions of Neymar and Kylian Mbappe for this campaign mean that anything less than a semifinal appearance in the Champions League will not really be considered good enough.

Although defending champions Madrid represent a significant hurdle for Emery and his men, something that the PSG hierarchy do recognise, failure to progress to the quarterfinals will mean that Emery's current contract -- expiring this summer -- will almost certainly not be renewed.

The source said the Ligue 1 leaders are not planning too far ahead for now but that sporting director Antero Henrique and chairman and CEO Nasser Al-Khelaifi have started to draw up a shortlist of names in the event that Madrid, or another side later in the competition, beat Les Parisiens.

Chelsea boss Conte and former Blues and Tottenham coach Villas-Boas are currently the leading candidates, with Manchester United boss Jose Mourinho also among the contenders.

Despite his immense level of experience, uncertain future at Old Trafford and sudden interest in coaching in France after years of derogatory comments, though, the source indicated that Mourinho is a distant third on the list.

Conte could still be in a job come the end of the season despite his frustration over transfers, but Villas-Boas is currently a free agent after leaving Chinese Super League side Shanghai SIPG and he will compete in the Dakar Rally this month.

The source said PSG's reasons for considering Conte and Villas-Boas ahead of Mourinho are their interest in the pair's man-management skills -- because of the number of egos in the dressing room -- and their desire to see the club maintain an attractive style of play.

Conte's motivational qualities greatly appeal, while Henrique is a big fan of Villas-Boas' blend of authority and aesthetically pleasing football from their time together at Porto.

At 40, Villas-Boas' age also makes him a potential long-term fixture, which is something PSG would love -- ideally with somebody who played for the club, such as Tottenham's Mauricio Pochettino, but at least a modern coach with many years ahead of them in the game.

Currently unattached, Villas-Boas is the obvious favourite to be approached for the job if Emery is dismissed but the source also said that the Spaniard could still be kept on if he can lead them to the Champions League semifinals or better.

Villas-Boas recently told O Jogo that Le Championnat in France is a league he would like to work in as a coach.

The ex-Porto and Zenit St Petersburg boss also revealed that he has rejected PSG once in the past when he was in charge of Spurs and Les Parisiens were looking for a successor to Carlo Ancelotti -- he was offered the job before Laurent Blanc was ultimately settled upon.

Villas-Boas cited his "good relationship with the PSG management" in a recent interview with The Times but he also stressed that their most recent contact was "not this year" and also admitted that, given how his time with Spurs ended in December 2013, things could have been different.

He said: "The day I turned down PSG [summer 2013], I was 100 metres from the place where the Tottenham management was staying. All the days previous to that I was never called in, never given a word of support or trust, never spoken to.

"I made the decision to stay because I loved the club and I believed the club could get better with the arrival of Franco Baldini [technical director].

"In the end it was a mess and the decision to part company was best for everyone."