Walker had to sit out Friday's 2-0 defeat to Chile because of a muscle problem, but after having a pain-killing injection, he is fit to face the Germans.
"I'm feeling fine and ready for selection on Tuesday," the Tottenham defender told FA TV.
Walker missed England's previous game against Poland through suspension, but he managed to take in the excitement of World Cup qualification from the stands after being given a few tickets to the game courtesy of the FA.
The euphoria that followed that win gave way to disappointment last week when Chile outclassed England to end a 10-match unbeaten run for Roy Hodgson's men.
Walker, who will earn his 10th cap if he plays against the Germans, says the whole squad is desperate to bounce back from the defeat.
"The mood here is always great," he added.
"We have some fantastic characters as well as players in the team, so it's always going to be buzzing.
"The defeat was a little bit of a downer, but luckily we've got Tuesday to put things right and hopefully we do.
"It's going to be a very difficult game. As a team we learned a lot on Friday against Chile, where they play the passing football, but I think it's going to be a little bit different to how (Germany) play.
"They have quality right throughout the team, but let's not underestimate us, we're a fantastic team, we've got quality throughout and I think it will be a fantastic game."
England have enjoyed some memorable matches against Germany over the years, the most recent one being a 4-1 drubbing at the 2010 World Cup.
It is therefore unsurprising that Walker picks out another match - the 5-1 victory 12 years ago - as his fondest memory of the rivalry between the two nations.
"I remember the 5-1, it's a good thing to remember when you're growing up," said Walker, who was 11 at the time of the famous win in Munich.
"I saw that game round at my friend's house.
"We always used to go to his house when England were playing, so I was probably round there with about five other mates.
"I wasn't involved with the Under-21s when they played them, so it's going to be a great experience if I'm selected.
"If I do get the chance then I will give my all and hopefully get the result that the players want, the fans want and everyone in the country wants."