By Timothy Collings

BUHLERTAL, Germany, June 29 (Reuters) England's 'golden generation' face their greatest, and possibly final, test in Saturday's World Cup quarter-final against Portugal, returning right-back Gary Neville said today.

Neville, 31, in line to win his 81st cap after recovering from a calf strain, said that several of the current group may never have another chance to reach a World Cup semi-final.

''People say that this is a golden generation (for English football), but that will only really be decided in moments like Saturday afternoon,'' he said. ''Then we'll see.'' Neville has missed the last three games, two in the group stages and last Sunday's dreary 1-0 victory over Ecuador in the second round.

He said he believed England's squad is mentally strong enough to cope with the pressure and criticism they have experienced.

''I said right from the start that we have got a good group of players with a very strong mentality. To play and get results, when you are not at your peak, is a sign of that strong mentality.'' Along with captain David Beckham and central defender Sol Campbell, Neville is in the 'over-30's' club. He will be joined before South Africa in 2010, by eight other members of the squad.

''This is one of many big games that a lot of the players have played and what an opportunity it is,'' he said. ''We've got a chance on Saturday to go through to a World Cup semi-final -- and these don't occur very much in football players' lives.'' He said that four years earlier in Japan, the humidity, England's relative lack of experience and an 'exceptional' Brazilian team were all negative factors for England.

''But now, we are playing Portugal in a better climate, with more experience and we hope the temperature will suit us better, as well.

''There is a belief in this squad now, four years down the line, a belief that has been with us since the very beginning that we can do something very good at this tournament and that hasn't changed at all.

He added that England had ''four or five'' potential match-winners in their team. ''I think that's another area in which I think we are stronger than we were three or four years ago. They can affect the game and, hopefully, on Saturday, one or two of them will do that.'' Neville warned, however, that the prospect of meeting forwards like Luis Figo and Cristiano Ronaldo meant the England defence would be fully tested.

''The thing with playing Cristiano is that you can play brilliantly for 89 minutes and then he can produce that magic moment in the 90th. It is only when you come off the pitch -- and he's not scored or set up a goal - that you can say you did well against him.'' REUTERS DH HT1917