Portsmouth do not expect Warnock, who has been offered a three and a half year contract, which doubles his £400,000 salary, to agree to join them until after Saturday's Sheffield derby. They are still hopeful that the 57-year-old can be appointed at the beginning of next week and are sympathetic to his position, and confident he will leave Bramall Lane, although he is also understood to be awaiting a counter-offer from United.
In the meantime Portsmouth will turn to McLeish and hope there will be developments in the next 24 hours. The Scot, who is greatly admired by the Portsmouth chairman Milan Mandaric, has already indicated that he wants to take some time out from football after he leaves Rangers. That will probably be after next week's Champions' League tie against Internazionale, but Portsmouth still believe he can be persuaded to join them instead. If neither Warnock nor McLeish accepts the post, Mandaric may still turn to Harry Redknapp, who has gained growing support among Portsmouth fans in the last few days even if he has publically said he would be "crucified" if he went back.
His return, a year after walking out of the club, to join their bitter rivals Southampton, would certainly be sensational. It may also be a step too far for Mandaric, although he is committed to getting the best man for the job.
It appears that Sir Bobby Robson has now been ruled out of the running, although a more feasible option is David Pleat, who would be appointed as a director of football, alongside a younger manager. That person would be appointed at Pleat's discretion and the list is thought to include Brentford's Martin Allen, Rotherham's Mick Harford and Ian Holloway of Queen's Park Rangers.
Another possibility would be Motherwell's Terry Butcher, who had initially been suggested to work with Robson, while Luton Town's Mike Newell is also being considered, although he lacks experience in the Premiership and, with his family still in the north-west, may not want to move further south.
Portsmouth, who have already been refused permission to speak to Crystal Palace's Iain Dowie, remain committed to appointing a British manager, and have set themselves a deadline of one being in place for the match against Tottenham Hotspur in 11 December.
Whoever comes in will be given funds to overhaul the squad in the January transfer window. Four attacking players - Laurent Robert, Azar Karades, Collins Mbesuma and Ivica Mornar - seem certain to leave while the club, now in the relegation area, knows that strikers are a priority. Robert, recruited by Alain Perrin, who was sacked as manager last week, was excluded by the caretaker Joe Jordan from the squad for the match against Chelsea.
Once again the French winger spoke out after the game, claiming that he was "angry and upset" and was aware that Portsmouth are trying to get rid of him.
"There are people at this club who are trying to get me out," said the 30-year-old, who was fined two weeks wages for his outburst when dropped against Sunderland recently. Robert also said that certain senior players had forced Perrin, who has achieved just four wins in 21 matches, to leave.