Pressure plays on them, but, in the imprecision of human behaviour, one can never anticipate how. Bobby Moore performed at his best when most was at issue. "The best defender I've ever played against," Pele said of him. Moore's attention often diffused over a long club season. Important games refocused it.
Manchester United's defeat of Juventus last week in the Champions' League resulted, in the main, from the sustained intensity of their teamwork. Much less was required to easily overcome Crystal Palace in a Premier League game at Old Trafford three days later. "You couldn't help feeling that some of the United players were bored," a Palace supporter said.
Put the fact of interrupted rhythm to coaches and they nod, curiously restrained. "I couldn't believe it," one recently said when referring to the sudden, mystifying collapse of a star player's form. "Our best man one week, our worst the the next. It can happen."
As Glenn Hoddle has grown to know, international football is a world apart, with its own set of imponderables. No matter how close the England coach's scrutiny, he cannot be sure that the men chosen to start against Italy on Saturday will be at their best mentally. A player can look great in rehearsals, but on the night he gives a poor performance.
The most successful of Hoddle's predecessors, Alf Ramsey, used to explain his position this way: "It's mostly about selection, not asking players to perform tasks that make them uncomfortable." Ramsey's great rival, Helmut Schon of West Germany, said: "You don't cling to outstanding players, they cling to you because of their intelligence and willingness to work for the team."
Hoddle was understandably encouraged by England's successful effort in the Tournoi de France, but a view held here is that too much was read into a victory over Italy that figures prominently in assessments of this week's proceedings.
A traditional feature of England's national team is to play flat out whatever the circumstances, their commitment as complete in friendly matches as World Cup ties. An impression gained from watching last summer's encounter on television was that England took it more seriously than their opponents.
In their dogged refusal to accept this, some pundits are as perilously placed as horse players blind to evidence of deliberate idleness in running.
Does the recent history of English football tell us anything more important than that Italy, through a resolute act of will and technical superiority, held their ground to win at Wembley? I don't think so.
Even with such notables as Franz Beckenbauer and Gunther Netzer in the team, West Germany gave themselves little chance of holding England at Wembley when attempting to qualify for the 1972 European Championship finals. "Even though we'd defeated them in the 1970 World Cup everything seemed against us," Beckenbauer said. "We were nervous in the dressing- room because England had many fine players and appeared very confident, but the breaks went our way and we surprised a lot of people including many of our supporters by winning 3-1."
No great significance should be attached to the fact that it is 36 years since England last succeeded on Italian soil, although Hoddle will welcome a repeat of the good fortune evident in reports of the 3-2 victory on 24 May 1961.
Doubtless people find it encouraging when somebody in Hoddle's position speaks about sending a team out to play positively but a pretty safe bet is that England, with the advantage of two options, will sensibly seek to establish a balance.
And while it is important today for a football coach to be well schooled in strategy and tactics, nothing matters more than individual ability. There has been enough evidence lately to suggest that English football has made technical advances. Enough to achieve victory in Rome? I doubt it.