Teams that grow up together also grow old together.

So the dilemma for any manager or head coach running a successful sporting unit is how – and, most pertinently, when – to make changes.

Some are forced anyway, by injuries, retirements or players deciding they would be better off somewhere else.

For domestic cricket the matter is more complicated. Should England decide to award a central contract, control of that player passes to the ECB and then they decide when and how often he will be available. Given the extensive international programme which now stretches through much of the year, that tends to be only occasionally and even then stipulations are often made on how many overs a bowler can deliver.

Covering the gaps with signings from elsewhere is not straightforward either. There is a salary cap – with a modest London weighting – and overseas recruits are becoming increasingly difficult to source. Not only do their own countries also have busy programmes and central contracts governing activity but government regulations mean work permits are harder to gain than of old and take longer to secure.

And overlaying the whole scene are the franchise leagues, such as the Indian Premier League, which can afford to offer often eyewatering amounts of money for comparatively short periods of work.

But within all those qualifications, a team manager must constantly refresh his squad in order to satisfy the demands for success. Any team winning a number of trophies will inevitably be closeknit, so breaking it up must be done with as much care as possible, yet with one of Bill Shankly’s dictums in mind: You have to change a team before they change you.

Shankly might not have agreed but in his time building Liverpool FC’s might, from 1959-74, he had it relatively easy: He could go out and buy a player or two.

Cricket has never worked like that – thankfully – although financial resources will always be an advantage. Much of Surrey’s recent success has been built upon a unit of players produced within the county’s youth network, supplemented by external and overseas signings. The team which have won three successive County Championships, and are just ten points off the top of Division One at the midway point of the current campaign, possesses several players in their 30s and perhaps getting towards the final stages of their careers.

How painful will the transition be? Surrey’s history is full of highly successful periods – the 1890s, 1950s and turn of this century – intermingled with long, barren spells in which trophies become just distant hopes and memories.

The signing of Adam Thomas is one pointer to the future. The 18-year-old was handed his first professional contract last week after coming through the county’s talent pathway, which he joined aged 11. Like Martin Bicknell, Ashley Giles, Jade Dernbach, Rikki Clarke, Ollie Pope, Will Jacks and Shoaib Bashir – all England internationals now – he thrived playing for Guildford and made his Surrey debut last year in the Metro Bank Cup.

Thomas will join Ollie Sykes and Josh Blake in bidding for batting places as Surrey’s line-up begins to evolve over the next year or so and it will be a question for head coach Gareth Batty and Alec Stewart about how that process takes place.

By Richard Spiller