According to the agent, Paul Stretford, Collymore declared himself unavailable during the morning due to illness. However, sources close to Gregory suggested a different version of events. In it, the player told a member of the backroom staff that he did not feel mentally attuned to the role of substitute for which he was earmarked. The message was relayed to Gregory, who is said to have then instructed Collymore to stay away from the game. A meeting was later arranged for this morning, when it will be spelled out to the former Liverpool and England player that he no longer figures in Villa's plans as they bid for their first championship since 1981.
Gregory, normally a compulsive communicator, tried hard to keep his counsel after the match, meeting initial inquiries about Collymore's absence with a terse "no comment". But it quickly became evident that he felt betrayed by a player who was widely perceived as problematic long before he inherited him from Brian Little.
The Villa manager said: "I've stood by Stan Collymore since the day I walked through the door last February. I've tried to back him in everything that has gone on while he has been at the club. I've been extremely supportive but it remains to be seen whether I will continue to do so."
Despite being without Dion Dublin, Gregory originally planned to start Collymore on the bench against Fulham. But because of "circumstances beyond our control", he decided to "let him stay away". He added pointedly: "Most players go off in a huff if they're not in the team, but some can cope with it better than others."
Asked whether Collymore would play at Newcastle in the Premiership next weekend, Gregory said firmly: "No."
Gregory's patience with Collymore is clearly exhausted. He stood by him when Collymore alleged that Liverpool's Steve Harkness had racially abused him during the new Villa regime's first match, 11 months ago. After Collymore admitted assaulting his then girlfriend, Ulrika Jonsson, in a Paris bar during the World Cup, Gregory offered him the chance to purge his demons by living up to his potential on the pitch.
More recently, following Collymore's dismissal against Liverpool for a violent foul in what seemed to be an ongoing feud with Harkness, Gregory restored him to the squad after his suspension. But he has started only two games since mid-November, being substituted at Charlton and scoring twice in the FA Cup tie against Hull City, and he has just one Premiership goal this season.
Gregory is acutely aware of how his predecessor was undermined, personally and professionally, by players flouting his discipline. Mark Bosnich stormed out before a fixture at Derby upon learning that he was only on the bench, while Little also had also problems with Collymore, Sasa Curcic and Savo Milosevic.
Already this year, Gregory has seen Paul Merson fly out to New York for an unannounced weekend break and Collymore complain via the media about his frustrations. Although the rift with the former Arsenal player was swiftly healed, it was the manager's preference for him as Dublin's replacement against Fulham that sparked the latest upheaval.
Villa might have trouble recouping a substantial part of their expenditure on Collymore. Nevertheless, Gregory has apparently decided that the price of letting him maintain a dissatisfied presence within the dressing-room is too high.
Finding a buyer in England might prove difficult in view of Collymore's troubled history, not to mention his wage expectations. Stretford has dismissed reports linking his client with Paris Saint-Germain, and it is surely fanciful to imagine Atletico Madrid considering a part exchange for Juninho, in whom Gregory has confirmed his continuing interest.
Collymore, who turned 28 last Friday, has generated pounds 18m in transfer fees without managing to recapture the explosive pace and shooting which earned him international recognition before he forsook Nottingham Forest for Liverpool. Villa, the club he followed as a boy, looked the ideal place for him to thrive, but now a parting appears to be imminent.
COLLYMORE: LANDMARKS IN A STORMY CAREER
1971: Born Stone, Staffordshire, 22 January.
1989: Walsall cancel his YTS contract. Wolves take him on as a trainee, then he joins Conference club Stafford Rangers.
1990: Moves to Crystal Palace for pounds 100,000.
1992: Leaves Palace. Joins Southend for pounds 80,000.
1993: Nottingham Forest manager Brian Clough refuses to pay Southend's pounds 2.2m asking price. Forest relegated and Collymore signs for Clough's successor Frank Clark for original fee.
1994: Hits 24 goals as Forest win a return to the Premiership.
1995: Acquitted of assault charge for alleged fight outside nightclub. Scores 25 goals in the season. First England cap against Japan on 3 June . Joins Liverpool for British record pounds 8.5m.
1996: Makes 44 appearances in his first season at Anfield and scores 19 goals. As new season starts, Collymore still commutes from West Midlands to Merseyside. Aston Villa fail in a pounds 6m bid. Fined pounds 20,000 for not attending training.
1997: Called up by England to play Mexico. Joins Villa in a pounds 7m deal. Sent off and handed a three-match ban for fighting.
1998: Accuses Liverpool's Steve Harkness of racist abuse during and after Villa's 2-1 home victory. PFA forced to step in as neither player backs down. Involved in an altercation with girlfriend Ulrika Jonsson in a bar in Paris. Makes public apology.
1999: Given a permanent place on the bench, he goes AWOL before Villa's FA Cup fourth-round defeat by Fulham.