The Liverpool defender is likely to get a rare start against Wales on Saturday - due to injuries to Campbell, who was at yesterday's session because it was held at London Colney, Arsenal's training ground, and John Terry as well as Ledley King - and knows it is an opportunity he has to seize.
"I haven't had a decent run for England yet," admitted Carragher, who has not started a competitive game before. "That's not a criticism of anyone, there's a lot of good players ahead of me. But it's difficult to be with England when you play the odd game now and again."
Such, of course, as the 45 minutes he endured in last month's friendly against Denmark. "To lose in that manner and to come on at half-time is the worst thing about it," the 27-year-old said of the 4-1 defeat. "It's not too good for your CV, coming on in a game like that."
Like the rest of the England squad he had to sit through a rerun of that game. "It [the video] was stopped and we all got a bit of criticism," Carragher said. "And rightly so."
He is also honest enough to admit that although he will earn his 19th cap, he has not made the most of his opportunities. "I've not really grabbed my England career with both hands," he said, "even when I've had a little chance.
"Every chance I get has got to be taken and, unfortunately, the way the [Denmark] result went, I didn't take it," Carragher said. "I can't be blasé about internationals because I'm not good enough to walk into the team."
Nevertheless, Carragher is certain that with "a little run" he will do better and, given the doubts over Campbell and Terry, he could be Rio Ferdinand's partner for the final four World Cup qualification games.Interestingly, he likened the Denmark defeat to last May's Champions' League final - when his Liverpool side came back from three goals down. "Sometimes these things happen," he said. "They come out of the blue, like the final."
His performance in last season's Champions' League led to Carragher being named last week as one of the best defenders in Europe by Uefa. Terry beat him to the overall title and Carragher said: "He's younger than me but I look up to him. He's a fantastic player, a great captain."
He, like England's coach Sven Goran Eriksson, expects a response after Denmark. "We've got big players who are at big teams and they're not used to getting beat," Carragher said.
One of those "big players" is his friend Michael Owen. He will be suspended against Wales and will also not now be reunited with Carragher at Liverpool.
"We have spent a lot of money on strikers," Carragher said. "£14m on [Djibril] Cissé, £7m on [Peter] Crouch, £6m on [Fernando] Morientes. Maybe the timing wasn't 100 per cent right."