The Gunners forward, who turns 21 next month, has seen his progress this season hampered by injury.
However, after a return to the Arsenal team, Walcott was called up to the England squad for the friendly against Egypt, and started at Wembley on Wednesday night before being replaced by Shaun Wright-Phillips after a largely ineffectual display.
Three Lions: Walcott featured against Egypt before being replaced at half-time
Walcott - who smashed a famous hat-trick in the qualifier againstCroatia at the start of last season - admits he cannot rely on pastglories to make sure of his place in Fabio Capello's final 23-man partyfor South Africa.
Wenger, though, feels the former Southampton man - a shock inclusionin the last World Cup squad four years ago - is on the right track,despite being an easy target for critics.
'For a while maybe people expected too much of Theo and now they are too hard with him.' said the Arsenal manager.
Injury-hit: Walcott has made just 13 Premier League appearances this season
'I believe Theo will be a great football player, he is very young, he will be 21 this year, he will have a great future.
'I believe in him because he has a fantastic attitude, he's anintelligent boy and he is highly motivated. These players alwaysimprove.'
Mentor: Wenger insists Walcott can be a great performer for England
Former England winger Chris Waddle questioned Walcott's Englandcredentials, claiming the youngster 'doesn't understand the game'. Wenger, however, defended his player.
'Don't worry for him,' the Arsenal boss said. 'I believe Theo hasnot only a football brain, but he has a brain - that means he willcontinue to develop at a very quick pace.'
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