For most of the last four decades the England left-back spot has operated as a kind of generational sinecure, passed down from hand to hand, with just the odd short-term lessee or temporary squatter in between. Through Kenny Sansom, to Stuart Pearce, Graeme Le Saux, Ashley Cole and now Leighton Baines it has been – barring the odd fling with a Hinchclife-Dorigo-Bridge-Neville quick fix – a fairly straightforward business identifying who at any given time is the incumbent England left-back.

It was only last spring that Baines finally levered out Cole, helped by Cole’s absence from the Chelsea team, his own sublime attacking form with Everton, and the good opinion of Roy Hodgson, who rates Baines highly both as a fine team man and an intelligent, forward-looking full-back. This is, though, still a succession with a slight air of impermanence about it.

It would be wrong to read too much into Kieran Gibbs playing the full 90 minutes against San Marino on Thursday. Gibbs played well enough given the uniquely flaccid nature of the opposition, and bearing in mind that his club colleague Calum Chambers still managed to have an oddly frantic first half on the other flank. There is no real suggestion that Gibbs is close, yet, to usurping Baines as a permanent first choice, and England’s current No1 No3 is likely to return against Estonia in Tallinn on Sunday.

But still, given the Everton man’s relatively poor World Cup, during which the shadow cast by Cole’s unrelenting tournament excellence hung over some slack defending in England’s two group stage defeats, it must be considered another area of slight flux for this chop-and-change England team. Right now the left-back franchise is, if not quite recruiting, then at least keeping details on file should a vacancy arise in the near future.

Which is, naturally, good news for Gibbs, so often struck down by his own physical fragility in the past but currently on an encouraging run of six starts for Arsenal – these things are relative – since his return from a hamstring injury. San Marino was Gibbs’ first competitive start for England at the age of 25, having been selected first by Fabio Capello four years ago, a reflection of his tendency to break down with injury just as his considerable talent begins to assert itself.

Gibbs played 34 matches for Arsenal last season, 29 the season before and 19 before that. If he has too often seemed to be in and out, never quite as robust as his mobility and fine physique suggest, then throughout he has remained a consistent defender and a quietly potent attacker, mustering three goals and seven assists during three interrupted seasons.

More to the point Hodgson has a genuine choice here when it comes to left-back, with Gibbs versus Baines a matter of style as well as personnel. Both like to attack, but there is a difference in the texture of their full-back play. Baines has more craft on the ball, a genuinely fine left-foot delivery, and – with Everton, if not England regularly enough – overlaps fearlessly. Gibbs is a more impressive athlete and quicker across the ground. He does not so much overlap as press high up the field when his team is attacking, occupying a forward position with aggressive intent and looking to link around the edge of the penalty area.

It is the way of a certain kind of mobile modern full-back, the player who condenses the area in font of him and trusts his speed to chase down an opposition break into the space left behind (to his credit Gibbs has a low foul count and is rarely booked). Luke Shaw – when fit and playing well – has a similar style, a high-pressure presence engaged as much in pressing his opposite number back as running in behind him.

Either way left-back at least offers options rather than simple uncertainty. Both full-back positions have been something of a revolving door recently, but right-back is the more obviously troublesome. Baines and John Stones started at full-back in the friendly against Norway and the qualifier against the Swiss, followed by Gibbs and Chambers on Thursday. Before that Shaw, Phil Jones, Glenn Johnson, Cole, Chris Smalling, Kyle Walker and James Milner have all played at full-back at least once this year.

Baines will have a chance to reassert his first-choice status on Sunday night at the A Le Coq Arena. But if Gibbs can stay fit he offers some serious competition – and Hodgson a genuine choice.