The Arsenal winger came off the bench to score a goal and provide an assist to help England beat Sweden, but hopes to be more than just a late game changer for the national side
The Arsenal winger replaced James Milner on the hour mark with England trailing 2-1, and scored the equaliser before bursting through to provide the assist for Danny Welbeck's late winner.
After his impressive cameo, the 23-year-old is hoping to start the decisive final group game against Ukraine on Tuesday.
"I don't want to be known as a super-sub," Walcott told The Mirror. "But you have to be ready to come off the bench and make an impact if you're not in the starting team.
"This game isn't just about the 11 players who are picked. You have to rely on the 23 players who have been selected for the tournament.
"I have waited for my moment and hopefully I've taken it, but there are other players in the squad who will want to do the same thing. It's all about waiting for your chance - and when it comes you have to be ready.
"I was disappointed not to play against France, but that's a good thing. There is huge competition for places now, with Danny Welbeck and Andy Carroll doing well, and we've got Wayne Rooney coming back for the Ukraine game.
"But I have scored one and helped set up the winner, so I think I have played my part. The boss [Roy Hodgson] said to me during the week that this game was going to be crucial for me."
Walcott is now looking ahead to England's final Group D clash, when they take on co-hosts Ukraine knowing that a draw will be good enough to secure their place in the quarter-finals.
"They are the hosts, they need to win, and they will have all the support behind them, so it is going to be a difficult night for us.
"But we can't go into games looking for draws. We can't try that against Ukraine. It will invite trouble.
"Defensively we were great against France. People will say we didn't defend too well against Sweden, but our attacking play was very good.
"Hopefully it will all come together for us against Ukraine and we can produce the perfect performance."