Chairman of selectors David Graveney stressed on Friday the importance of picking the right characters to supplement the team.
All 12 of the players who represented England in the Ashes are set to be named in the touring party on Monday alongside four other players, whose roles on the trip may be little more than bit-part.
That quartet will be made up of an understudy to wicketkeeper Geraint Jones, a second spinner, at least one fast bowler and possibly an additional top-order batsman.
There are plenty of individuals vying for a spot - a 17th name could be announced to stand by should Simon Jones need surgery on his ankle injury - and temperament is viewed at the same level as ability by the current management.
"People have said the success of your touring party comes largely down to the quality of your back-up players and there is some logic to that," said Graveney.
"You can have problems with illnesses just on the morning of the game. So the choice of back-up players are people who are comfortable, if you can say that, playing at a short moment's notice."
One of the biggest points of debate is who will be sent as reserve gloveman with Nottinghamshire's Chris Read and James Foster, of Essex, both of whom have Test experience, facing the challenge of Sussex batsmen-cum-wicketkeeper Matt Prior.
Ironically, while Read is viewed as the best in the country behind the stumps, his 2005 first-class batting average is also far superior to his rivals.
Read, 27, originally lost his place due to coach Duncan Fletcher's preference for a batsman who could keep, rather than a keeper who could bat.
The fitness of Simon Jones - which will not be known for at least a week - has complicated the issue as to whether the squad opts for spin or pace.
Gareth Batty has been spinner Ashley Giles' deputy in recent times but he has endured a barren summer for Worcestershire while Gary Keedy, Monty Panesar, Graeme Swann and Alex Loudon may also enter the spin equation.
"Simon Jones' fitness report is relevant to that decision," Graveney added.
"The current situation is that he is resting for a fortnight and we'll have a closer idea what the implications are then.
"You can't cover all the bases. We have to decide whether we need two extra batsmen or two spinners, or two seam bowlers."
Both Test and one-day squads will be revealed on Monday.