Beckham is desperate to earn his 100th cap in next month's friendly with Switzerland and has been training with Arsenal during the Major League Soccer close season.
"I'm there to get my fitness for the MLS season and also to try to get fit for the England game," said Beckham, who was on Sunday night the guest of honour at a gala evening in central London.
"Even if it wasn't just for the 100th cap, for an England game I'd do the same.
"I want to be fit and be available for Mr Capello's first team and first game."
Beckham revealed his fitness after a five-week break from football had surprised him.
"It's a lot better than I thought it was," he said on Sky Sports News. "I feel great. I've had one day of training with the Arsenal team and three days of training with the fitness trainer."
Beckham revealed he had thoroughly enjoyed working with Gunners boss Arsene Wenger in the past week.
"It's been great. I'm lucky that Arsene Wenger has given me the chance to train with the team," he added. "It's nice to be with a Premier League team that is obviously so talented.
"The players have accepted me really well."