Whenever Arsène Wenger and Sir Alex Ferguson harp on about the fresh-faced teams they are building there is a faint implication that a grizzled Chelsea will seize up eventually. Old age, though, is as puny a threat to Jose Mourinho's plans as Arsenal and Manchester United themselves. Of the three, it was Chelsea who fielded the youngest line-up this week.
The side they sent out at West Ham on Monday had an average age of under 26. The figures for Wenger's and Ferguson's sides in Tuesday's insipidly goalless draw were respectively 27½ and 26½. The United and Arsenal managers are not so much prevaricating as overstating their case. It is indeed remarkable that Cesc Fábregas, at 18, has been steeped in Premiership experience with Arsenal. The callowness of Cristiano Ronaldo, 20, also makes it possible that he will realise that learning how to cross is far more relevant than brushing up on step-overs.
References to a player's youth, however, are generally made only to excuse the deficiencies. When Arjen Robben is under discussion, the issue of his fitness might arise along with the state of his relationship with Mourinho, but he is a year older than Ronaldo and younger than José Antonio Reyes, who still needs to be coddled at Arsenal. So long as the Dutchman can arguably be considered Chelsea's most devastating attacker there are better things to talk about than his date of birth.
Managers often call for patience to be shown to players of great potential in the hope that they can siphon off some of that tolerance for themselves. Perhaps they teach this ploy on the Pro licence course or maybe each generation of dug-out occupants just passes it on to the next. It is something of an indignity for rightly admired managers such as Ferguson and Wenger to recite the well-worn words but there is no alternative at the moment.
Ferguson has had to dust down the strategy. He talked of his "new team" before the home draw with Villarreal and argued, after Benfica had eliminated United in the group stage of the Champions League, that "we are rebuilding, waiting for players to mature". No one will be as hard-hearted, however, as an owner who has purchased a club, particularly when the bill came to around £800m. The Glazers will want to know how soon a challenge to Chelsea can be mounted and the Americans do not need to have football genes to work out that United were nine points behind Mourinho's side at this stage last season and are currently 13 adrift.