It was during a training ground chat with Danny Rose, a talented young winger on loan at Bristol City from Tottenham and a member of England's youth team, that I got to thinking: what is the point of England under-21s?

The Championship is littered with former England under-21 players, most of whom never made it to the senior squad. Some of our best English players never seemed to bother with that level of football – Wayne Rooney never played there (he had one appearance for the under-19s before going straight to the senior side the following year); Michael Owen played just once for them.

If you look at the list of most-capped players at under-21 level, only three were selected for the World Cup squad this year: James Milner, Gareth Barry and Jamie Carragher (who came out of international retirement for the competition). Of the rest, players such as Jermaine Pennant or Steven Taylor were never called up to the full England side, and Scott Carson and Tom Huddlestone hold three caps apiece.

The statistics alone would suggest that being selected to represent England at under-21 level does not equate with being a talented enough player to perform for the senior side. If this is meant to be the feeder team for the senior England side, is it working?

I put the issue to the lads in the dressing room and we had a good discussion. Their general consensus was that the under-21s serve primarily as a great shop window – the best route for a young player to command better club contracts. That doesn't do much for our national ambitions.

The chat quickly went round the physio room, and by coincidence it turned out that Stuart Pearce was at our club the same day. Steve Wigley, our assistant manager, called him in to join the discussion and all the lads gave me a funny look as if to say: are you really going to ask the England under-21s manager if there is any point in having the England under‑21s? I did feel a bit cheeky but Pearcey was great and didn't see a problem. We sat down together and as you would expect he produced a compelling argument, citing the example of Spain who were successful at under-21 level and then went on to win the European Championship and the World Cup. No one's going to argue with that.

But a nagging thought remained. As it is, the England structure relies heavily on young players progressing in a strictly linear fashion. So, what if you're a late developer? You miss the under-21s boat and never get a chance to play for your country? Look at Kevin Davies, making his debut for England aged 33. The last time he was involved in the national set-up was for the under-21s 10 years ago. An entire decade passed without any international involvement. How can that be a good system?

With goalkeepers the situation is even more critical. Keepers tend to mature in their late twenties so how does the under-21 set-up work for them? Even if you are developed enough at youth level to play for England, what do you do with yourself in the intervening years before you receive a senior call-up? I was 27 years old when I made my full England debut, having had a six-year gap since my last call-up to the England under‑21s. Even after that first full debut there followed a three-year wait for my second appearance.

Clearly there's a massive void between the under-21s and the senior national side, and we're potentially missing out on talent – either players who have developed later in their career, or losing people through the gap between the two squads.

For me the whole England set-up is far too much like an event horizon: if you're not in it you have no idea what's going on in there, how it works, or how to be a part of it. You're frozen out.

Which is the point where the England B team used to come in. It's not glamorous, it won't get you a big-money contract anywhere, not many people bother turning up to watch you and you get a funny coloured cap when you play, but I would argue that it does help the England coaching staff to identify talent for the senior side. And it helps the player by giving him a chance to be involved in the national set-up – from playing international football to just being part of an England camp. Best of all, there is no age discrimination.

Otherwise, it seems, if you want to be successful in international football you had better do it while you're young or miss out forever. As someone interested in coaching, I worry about an attitude that assumes if you haven't done it already then you will never do it. That's far too simplistic an approach and it says everything about this throwaway world we're in: he's had his chance, it didn't work out so let's get a new one. The B team can work as a vehicle to rejuvenate players who were in the frame at one point and are now out of it because of their age. We haven't had an England B team fixture since May 2007. Maybe it's time we brought back the Bs.

David James has donated his fee for this column to charity.