With Mackay adamant he has no intention of quitting, it appears inevitable that the manager will be dismissed. The only question is when.
Mackay is due to attend a press conference at Cardiff's Vale of Glamorgan training ground on Friday, before flying to Merseyside for Saturday's Premier League fixture at Liverpool. There is a growing sense that the game at Anfield could well be Mackay's last in charge of the club he led to promotion last season, sealing their return to the top flight after a 51-year absence.
The relationship between Tan and Mackay has been broken beyond repair for some time – Mehmet Dalman, the chairman, has been acting as a go-between – but this week's extraordinary events have brought matters to a head. The owner, having publicly criticised Mackay in a remarkable club statement released on Monday, when Tan said that "not a single penny" would be available to spend in the January transfer window, sent the manager a remarkably long and detailed email, outlining a list of grievances that culminated in him ordering the 41-year-old to tender his resignation or face being fired.
Within that email it is understood that Tan is critical of results, the playing style, some of the signings made in the summer, when the owner alleges that the club spent £15m more than was budgeted, and even rows back on Mackay's record while in charge at Watford and draws comparisons with how Cardiff performed at the same time under Dave Jones.
In a bizarre twist on yet another head-shaking day at Cardiff, Jones, who took legal action against Tan after his sacking as manager in 2011, has emerged as a possible candidate for a director of football role at the club.
With Mackay not entertaining any thoughts of walking away from Cardiff, Tan is expected to carry out his threat at some point over the next few days and make a decision that will go down extremely badly with the club's supporters – there is already talk of a possible protest against the owner before the Boxing Day match at home to Southampton. It will also cost the Malaysian businessman a significant seven-figure sum in compensation, something he has been doing his best to avoid.
It is believed that Cardiff have already started to consider possible replacements for Mackay, including Ole Gunnar Solskjaer and Roberto di Matteo. Gianfranco Zola could also come into the frame. Given that Solskjaer, who is in charge of Molde, has spoken in the past about Sir Alex Ferguson advising him to choose an owner rather than a club when it comes to management, it seems difficult to believe that the former Manchester United striker would warm to the idea of working under Tan, whose reputation for interfering and making unfathomable decisions now precedes him in the world of football.
Brendan Rodgers, the Liverpool manager, accused the Cardiff owner of knowing "absolutely nothing about football", which is pretty much what the managing director of one of Tan's many companies said in a filmed conversation in Malaysia earlier in the year. "He doesn't know any rules about football," Al Chuah claimed, laughing. "It doesn't matter. It's another new business," Tan said, smiling.
For Mackay the reality is that the writing has been on the wall ever since Iain Moody, his head of recruitment, was sacked in October and replaced with Alisher Apsalyamov, a 23-year-old from Kazakhstan who had no previous experience of working in football. Apsalyamov, in another farcical development, was subsequently forced to stand down because of a problem with his visa. Moody has denied Tan's accusation that he went over-budget last summer.
Despite everything that has gone on, Mackay was hopeful that he might be able to see the job through to the end of the season and keep Cardiff in the Premier League in the process – which is on the cards, with the Welsh club in 15th place, four points above the relegation zone.
In his previous two years at the club Mackay lost to Liverpool in the League Cup final and reached the Championship play-off semi-finals in his first campaign, and won the Championship title in his second season. Quite what Tan expected from this term is anyone's guess.
"I find all the talk about Malky incredible," said Rodgers, a friend of the Scot's since their time together at Watford, speaking before it emerged that Mackay's time at Cardiff is up. "He is going to become a big manager at a top club and I find it astonishing that there is talk about him leaving. Absolutely astonishing.
"My only conclusion when I look from the outside is that you have a business guy operating the club who knows absolutely nothing about football."
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