Since enthusiasm was central to the immense reputation Keegan forged as a player and the excitement he generated as manager of Newcastle United, no wonder that England are not expected to want for passion in their European Championship qualifier against Poland at Wembley on Saturday.
Not so much tactical nous and technical accomplishment as the will to win. Certainly, it is well established that nothing much can be achieved in sport without putting in maximum effort but, as any number of football coaches have learned to their cost, battle cries are not all they are cracked up to be.
Only last week, Tottenham's director of football, David Pleat, after overhearing a supporter's assumption that George Graham would wind his players up for the Worthington Cup final against Leicester City, said: "They'll be on a high anyway, so George will probably think it more important to wind them down."
The self-inflicted knee injury that permanently reduced Paul Gascoigne's effectiveness resulted from firing himself up before playing for Tottenham against Nottingham Forest in the 1991 FA Cup final. "Once Paul got out there, it was clear that we hadn't done enough to calm him down," Terry Venables has since said. "You want players to be keyed up but there can be a downside to excitement."
All this stuff abut motivation gives rise to some interesting questions. What is this quest for character coaches are always going on about? And courage, momentum and pride? Where is the pride in a footballer who needs stimulation to play in a big game?
One thing we have to remember is that many players are so occupied by their small piece of the action and so preoccupied with themselves and their fears that they really have no conception of the big picture of the team or the game.
No manager in history is credited with greater powers of motivation than Bill Shankly, who saw enough in Keegan's enthusiasm to sign him for Liverpool from Scunthorpe. Shankly's talent for popular imagery is best represented by a tale John Toshack told one night about an FA Cup semi- final replay between Liverpool and Leicester at Villa Park earned by Peter Shilton's exceptional goalkeeping.
"Surprisingly, Bill didn't show up in the dressing-room until shortly before the kick-off," Toshack recalled. "He just stood there looking at us, hands thrust into the pockets of his raincoat. `Imagine,' he said `that you are being battered by George Foreman [at the time world heavyweight champion] and the lights go out and you have to do it again. That's how Leicester feel.' Then he was gone. Perfect. Bloody perfect."
Matt Busby argued that excitable managers sent out excitable teams. To my mind it is no coincidence that England were most successful when the dressing-room was calm and there was a sense of adult responsibility. "We were always ready, often nervous too, but never worked up," George Cohen, of the 1966 World Cup winning team, recalled. "Nobby [Stiles] was always full of it, but the mood was set by Alf [Ramsey] and Bobby [Moore]. When the call came, Bobby simply picked up the ball and said: `Let's go'."
Bearing that in mind, if Keegan has made a mistake so far it is in preferring Alan Shearer to Tony Adams as captain. Adams' old reputation as a fist- waving influence has given way to such composed authority that he has never played better or had more respect.
Whatever footballers feel, whatever tingle of anticipation lights up their minds and feet, the significance of a downturn in fortunes is that it makes passion suddenly less relevant, even a burden.
In any case, it would seem that professionals, who by definition are supposed to perform at a high standard, who have highly lucrative careers at stake and families to support and egos to bulwark and team-mates to join in a common cause, have enough natural stimulation without the jive of coaches and managers.