Sam Wallace: Manager's flexibility offers break with past and gives opportunities to outsiders

Capello has a few decisions to make (GETTY IMAGES)

When the World Cup finals came around Sven-Goran Eriksson was accustomed to giving his England players certainties; Fabio Capello has given them a competition.

There are a handful of surprises in Capello's squad, not least his U-turn to include Gareth Barry, but what is most striking is just how fluid the hierarchy of these 30 names has become. With Eriksson there was the 23 and then there were the reserves – the chosen ones and the rest. With Capello the lines are not nearly so defined.

It will be hailed in some quarters as another blow for Fabio's regime of the iron fist, although you could also make a strong case for saying he is desperately buying himself more time for injured players to recover. What is not in doubt is that it has created a very different dynamic in the run-up to the final selection of the 23 on 1 June.

Let us not kid ourselves: the likes of Wayne Rooney, Frank Lampard and John Terry will not be anxious about whether they will make the final cut. But lower down the scale there are arguably 12 players who cannot be completely confident that they will be in the final squad. The clubby, secure atmosphere of the past is gone and there is an edge to the preparation that has been missing in the past.

Leighton Baines or Stephen Warnock? Capello has bought himself more time to decide. Matthew Upson or Michael Dawson? The manager will get back to us on that. In fact, the answer to that question might well be that they both go if neither Rio Ferdinand nor Ledley King come through the next few weeks unscathed.

And nowhere more than among the unprecedented 12 midfielders Capello (above) has selected is there more competition. From a group of players including the injured Barry as well as Tom Huddlestone, Scott Parker, Joe Cole, Adam Johnson, Michael Carrick and Shaun Wright-Phillips, the England manager will have to lose four by the time he departs for South Africa. It promises to be brutal.

As for Darren Bent or Emile Heskey, that should be the easiest of the questions facing Capello given that Heskey has been one of the mainstays of his team when fit. But, in his current form, you would not bet against Heskey giving the manager second thoughts.

It is a very different scenario from four years ago when Eriksson named a squad of 23 and five "stand-by players" – a group that included the extremely unhappy Jermain Defoe who had just suffered the indignity of being left out in favour of the 17-year-old Theo Walcott. Those five players followed England around in their preparation with no hope of a place on the plane unless one of the chosen 23 were struck by injury.

In 2002, Eriksson picked just one stand-by player, Danny Murphy, who replaced Steven Gerrard and in turn had to be replaced by Trevor Sinclair. Under Eriksson there were certain players who would be in the team even if they were playing on one leg – and the inclusion of David Beckham in 2002 and Rooney in 2006 suggested that one working leg was all that Eriksson required.

But we should not get too carried away exulting Capello. He has not had a good week with a major strategic error over the launch of his online player rating site, the "Capello Index", which was immediately dropped when it was exposed in yesterday's newspapers as a huge potential embarrassment. There were advisors who told Capello that before he went ahead with it on Monday but the England manager did not listen.

He has also proved that, despite his early hardline stance on refusing to pick players who were not completely fit, he too cannot resist an optimistic medical bulletin. Barry, Ferdinand and King are all major risks and although Capello has the scope within this 30 to cover for them, he will not be able to cope if there are further injuries to, for example, his centre-backs during the tournament.

It might seem a far-fetched notion that England could suffer more injuries in a position in which they already have players who are struggling but stranger things have happened. By including injured players in the first place, any manager risks putting himself on the back foot immediately.

Like Eriksson, Capello is wedded to the way in which he wants his England team to play and it is difficult for him to accept that important components of that vision – in this case Barry, Ferdinand and even King – cannot be part of it. Like Eriksson with Beckham in 2002 and Rooney four years later he is determined to soldier on nonetheless, and try to give those players the best chance possible.

Compared to the last two World Cup squads this is a more competitive, better equipped group. Capello has injuries to cope with, as England did in 2002 and 2006, but as long as he is prepared to make some difficult choices on 1 June and leave those behind who are not ready then he will have taken an important step away from the complacencies of the past.