If something deep inside you slackens so that to run your heart out no longer seems worth the effort, well, that's it...

"Strachan, Waddle, McGrath, Beardsley - these days, it seems players can on on for ever" is currently making a bid to be the most overused of football writers' stopgaps. Overused and, very arguably, inaccurate. Although I might be minor league evidence for the endless Indian summer theory - 36 and still playing - I have strong doubts as to whether there are more old men out on the park these days than, say, when England won the World Cup.

Thirty years ago there were approximately 5,000 registered professional footballers in the English game, twice as many as there are now. Sheer volume, therefore, was always enough to ensure that a lucky handful survived the physical perils of the park to reach a ripe old playing age.

Luck, good or bad, is always going to be the biggest factor determining a player's final games tally. As Dave Busst's career-ending injury last season most sickeningly reminded us, a split, leg-splitting, second, can end everything on the spot. But over the decades how many others have had to limp permanently off the field in early career, victims of Sod's Law? Tony Green, Brian Little, Gary Shaw, Jim Beglin, Danny Thomas, a few star names in a depressingly long list...

More weightily, though if less dramatically, for all such essentially crippled out of the game at one fell stroke, there have been countless talented pros who, sustaining a severe knock early on in their careers, routinely - "run it off, it'll be all right, son" - soldiered on never to regain absolute fitness again. Losing pace and place, slipping down the divisions, they sooner rather than later made their low-profiled bows to the inevitable. It's as true now, I'm sure, as it has ever been.

All the same, from those past eras (and setting aside the one-off case of goalkeepers - Jennings, Stepney, Ronnie Simpson, Shilton) a balancing list of "play 'til they got their pensions" names comes over even more readily to mind: Terry Paine, Jimmy Dickinson, Tommy Hutchison, Billy Bonds, Jim Langley, Tom Finney. Over-topping all, of course, in longevity, the incredible Stanley Matthews.

Position naturally impacts strongly on how long you last. Your average defender will stay longer than your average forward. (Matthews and Paine were wingers who didn't chase back. Work-rate in '66 was less punishing than a generation on). The point is made by the career of perhaps the finest post-war leader of England's forward line. After a long decade of service to Chelsea, Roy Bentley dropped back to centre-half and enjoyed the bonus of a few extended years with Fulham and Reading.

Today, of course, there are lots of artificial aids to playing longevity. Footwear is lighter, as is the lace-less ball; qualified physios are around a lot more; travel to away games is less wear and tearing; permitted body contact (charging the keeper; tackling from behind) is far more restricted. Above all, the introduction of the substitute has afforded many a grizzled veteran a sizeable helping of extra time: Andy Ritchie, Mark Hateley, Mick Harford, even, it has to be whispered, Garry Nelson.

At thirty-something, be it noted, the individual player's motivation is the starter for everything else. If you turn up for pre-season training and something deep inside you slackens so that the game of running your heart out in front of four thousand deriding fans no longer seems worth the effort, well, that's it. Good night, Rapid Vienna. It's worth stating - it's so obvious it gets overlooked - that players who keep on keeping on take enormous pride in what they're doing. They still enjoy it.

Not at all obvious is a political aspect of getting on in the game. Not a few 32-or-so year-olds, still with good performances to give, have found potential career-extending moves mysteriously coming to naught. The reason? They've been perceived as threats. Incumbent managers - the alleged officers of the game - have been known to balk at the prospect of senior NCOs, armed with a full FA coaching licence and 15 years shin-scarred experience on the park, signing for currently struggling City or United. Being too canny a football pro can positively reduce the life expectancy of a player, which the records of the Professional Footballers' Association show lasts, on average, an alarming eight seasons.

My wet finger in the air guess is that with television giving '90s football not only wall-to-wall but magnified exposure, the current crop of close to their sell-by date old boys are simply projected more into ad-mass awareness than their predecessors. I don't think there are more of them. It just feels that way. Tell you what, let Peter Schmeichel pick a pack of over-35-years-olds from the current game and I'll pick one from the past to take it on. You know, his Brian McClair, my Frank Worthington. I bet my lot beat his 10-0.