Bryan Robson insists Steve McClaren is being hampered by a lack of quality as England strive to qualify for the European Championships.
McClaren's men were booed off the pitch after Wednesday's 1-0 friendly defeat by Spain at Old Trafford ahead of two crucial qualifying away games against Israel and Andorra next month.
But former captain Robson urged the nation to get behind the manager and the team, claiming McClaren's problems are not all of his own making.
Speaking on BBC Radio Five's Sportsweek programme, Robson said: 'I do feel that it is lack of depth. When England have everybody fit and playing, they are a very strong side, they have proved that in the past.
'But, as soon as we get a few injuries to some of the key players, the lads who are coming in are not just up to it as far as beating the best teams and that is a problem for Steve McClaren.
'The one thing you can say though is that it is a great opportunity for some of these younger players to fight for a place. Micah Richards looks as though he will take to international football with no problems.
'But it is a centre-forward which we need to really come through and show they are capable of getting into the team and replacing either Wayne Rooney or Michael Owen if they are suspended or injured.
'That is the area that Steve McClaren will be monitoring a great deal over the next few months.
'If something was to happen to Wayne Rooney, or Michael Owen is not back, which doesn't look likely, he does have a bit of problem in attack.
'We don't really look as if we are going to score many goals when we play against decent sides.
'Wayne is a great player but it is a lot of put on one player's shoulders and, if we are not going to get goals from the forwards, he will probably have to look at the midfield lads.
'So, does he give Steven Gerrard and Frank Lampard even more licence to get forward to see if we can get goals from them?'
Another problem beyond McClaren's control is the lack of first-team football being played by some of those selected.
Liverpool's Peter Crouch, Chelsea's Shaun-Wright Phillips and Arsenal teenager Theo Walcott are all expected to step into the international arena when not playing regularly for their club sides and Robson has much sympathy for the England boss.
Robson added: 'Peter Crouch looked a little ring-rusty because he's not playing every week for Liverpool, Shaun Wright-Phillips is very similar.
'He looked as though he hadn't played much football because he cannot get a regular place in the Chelsea side.
'Theo Walcott is not getting in the Arsenal side and so it is a problem for Steve McClaren because the more experience and the more they play, the better they become.
'So, we are struggling and it is a bit of a headache for him at the moment.'
Despite the criticism heaped on the England boss after their soporific performance against the Spaniards, Robson still believes they will qualify for Euro 2008 and urged the country to get behind McClaren and his team.
Robson added: 'What we have got to do as a nation is get right behind the team.
'We have still got a great chance of qualifying and Steve McClaren can actually do that. We have got to give them great support when it comes round to the main games. I am sure the players are good enough to take us through.
'We have got to give the players and Steve the confidence that we know they have got the ability to do it.'