The fact that Curran's batting appears to have improved considerably of late - he has scored 47 not out, 31 and 29 not out in his last three ODI innings, demonstrating an ability to bat in different styles in the process - should cement his place. But his real skill remains his death bowling, where his well-controlled variations offer his side some hope of restricting batting units on the excellent batting pitches anticipated in the World Cup. Coaches and team-mates often mention his character, too: his apparent relish to be involved in the tense moments, which some players might prefer to avoid. It's an attractive combination. All but certain to be included.
The figures are unexceptional - Vince has failed to pass 43 in three ODI innings since his recall as a result of Alex Hales' 'deselection' - but the style with which he has made them has been encouraging. Much the same could be said about Vince's entire international career to date, to be fair (he has invariably looked classy in Test and ODI cricket, but averages of 24.90 and 28.12 do him few favours). But he has demonstrated a range of strokes and an ability to play in the fearless, positive style required by England. With Joe Denly not having been given an opportunity at the top of the order, it suggests nobody else is seriously under consideration for the role of reserve batsman. Vince is all but certain to be included but unlikely to play unless a first-choice batsman is ruled out.
Plunkett's record of taking wickets in the middle-overs - only ten men with more than 100 ODI wickets have a better strike rate in the history of the game - probably gives him an advantage over his fellow seamers. While there's little doubt he is, at 34, in gentle decline, he has the benefit of experience to mitigate against his drop in pace. Only Chris Woakes of the seamers in England's current squad has taken more ODI wickets and he continues to present an awkward challenge to batsmen with his cutters delivered from height and thumped in just back of a length. In a squad full of new-ball and death bowlers, he offers a point of difference and has earned the trust and respect of his team-mates and management over the last few years. He's not the most mobile in the field these days, but he still has a safe pair of hands and a strong throw. All but certain to be included; less likely to make the first-choice team.
Willey's unique selling point is the left-arm variation he offers and his ability to gain some swing with the new ball. But it is his misfortunate that England are, all of a sudden, pretty well covered in the area of new-ball bowling. With Mark Wood, Woakes and Jofra Archer all offering strong alternatives in that position, it seems Willey - who did not take a new-ball wicket in the Pakistan series - could be struggling to gain an opportunity. And while he is also good at the death - it's only a few days since his spell in Southampton all but settled a well-contested match - he might not be as good as Curran, Woakes or Archer. He is an improved cricketer over the last year or so, however - he has bowled his full allocation of ten overs in three of his six most recent ODIs, having not done so in 22 of his 23 ODIs before that - and decent with the bat and in the field. Could count himself desperately unlucky if he misses out but, realistically, the final place in the squad may be between him and Denly. And if England leave out a seamer, it's probably him. Faces a nervous wait.
Like a carpenter employed to do the plumbing, Denly's problem is that he is under consideration for a role - spin-bowling utility back-up - that doesn't really suit him. He has taken just one ODI wicket - and that was a stumping off a wide in the match in Dublin and has never bowled more than five overs in an ODI innings, either; he's only bowled 11 overs in total. In theory, he could offer top-order batting cover, but the fact he has twice been scheduled to come in at No. 7 and once at No. 5 does not suggest he is being seriously considered for it. Denly is, without doubt, a fine cricketer who would make a low-maintenance, high-quality substitute fielder as required in this squad, but he doesn't seem an especially comfortable alternative for any of the first-choice positions. Liam Dawson arguably remains a better fit for the role available - he is certainly the better spinner ...
Bearing in mind that he has not played for England this year, Dawson must be an outsider for a place in the squad at this stage. But it is worth remembering that he was in the squad in Sri Lanka until injury intervened - Denly was his replacement - and that, only a week ago, Trevor Bayliss, the England coach, confirmed that he was still in contention. He has enjoyed an excellent season in domestic 50-over cricket - only six men have taken more wicket in the 2019 competition; none of them can beat his economy-rate of 4.11 an over - and is a decent lower-order batsman in this form of the game. Looks unlikely to be included on Tuesday, but could still be called-up if Moeen Ali or Adil Rashid suffer injury.
George Dobell is a senior correspondent at ESPNcricinfo