The 21-year-old midfielder spent 17 months out with ankle and knee injuries, but returned to the Arsenal team this season, and has since established himself as the heart of the Gunners midfield.
His importance to England was demonstrated by the speed to which he returned to the Three Lions set-up - Roy Hodgson calling the youngster up for his sixth cap against Sweden last November.
Since then, Wilshere has pushed on, becoming the de facto leader of the Arsenal team.
And Walcott, who plays alongside Wilshere for club and country, believes his teammate has all the attributes to become one of England's best players.
"The way he's started after so long out is fantastic, Walcott said: "He's worked so hard to get back fit. To comeback into an England team at such a young age shows how good he is. He is mentally strong as well and he's only getting better. So he will not look out of place at all."
Brazil visit Wembley on Wednesday evening with Wilshere and Walcott expected to feature heavily for the Three Lions. And they won't face many sterner tests - Brazil coach Luiz Felipe Scolari has brought a strong squad to England, including the likes of Ronaldinho and Neymar.
Walcott, who first rose to prominence as a softly-spoken 16-year-old at the 2006 World Cup, is hoping to bring his impressive club form into the international arena.
The Arsenal forward already has 18 goals for Arsene Wenger's side this season, and with Jermain Defoe and Danny Sturridge sidelined, the Gunners attacker may feel he has a strong case to be named England's central striker against the Samba stars.
The report claims Walcott has played alongside Manchester United forward Wayne Rooney during England training, leading to speculation Hodgson could be prepared to grant him a central berth from the start against Brazil.