England manager Roy Hodgson has confirmed that Walcott is fit to start for Tuesday's final Euro 2012 Group D match against Ukraine.
The winger pulled out of training on Sunday after he complained of tightness in his hamstring.
Hodgson confirmed on Sunday night that Walcott's fitness was a concern: "Unfortunately he had a slight setback in training, and that's the major concern with him.
"He felt the hamstring and we were slightly concerned about that when he came to us.
"Whether he's a real contender for a starting position will depend to some extent on what the medical people can tell me and how much guarantee they can give me that if I do start him in the game he won't be leaving after five minutes."
But speaking after England arrived in Donetsk ahead of their match at the Donbass Arena, Hodgson said the Arsenal winger was in contention to start tomorrow night.
"He is fit for the game and luckily we don't have any other injury concerns," said Hodgson.
Walcott, who scored England's second goal in the 3-2 win over Sweden, insists he is capable of maintaining his golascoring streak if he is handed a place in the First-XI.
"People say I haven't really kicked on. I hadn't scored for England since my hat-trick in Croatia in 2010 but I'm still only 23 and I've now got 26 caps," Walcott is quoted in the Daily Record.
"That's not too bad, is it? The goals will come if I am playing games. I have always had that in my locker.
"This season with Arsenal there have been goals and assists. That's what it's all about as a winger because those stats are what you are judged on.
"Yes, there is still a lot to come. I have got a bit more experience now and featuring in this tournament can only be good for me. If I can keep clocking those caps up, it will all come together."