England winger Theo Walcott is uncertain whether his performance against Mexico will earn him a place in the final World Cup squad. [LNB] The Arsenal star took his place on the right for the majority of Monday's 3-1 friendly win at Wembley, only being replaced by Aaron Lennon in the latter stages of the game. [LNB]But while he admits he's putting all of his efforts into securing a place in Fabio Capello's 23-man squad for the trip to South Africa, he knows nothing is guaranteed. [LNB]"For me I just want to train well and if you train well then you hopefully get a chance to play," he told Sky Sports News.[LNB]"I don't think anyone's place is guaranteed yet so we'll be working hard like we did last week while training in Austria. [LNB]"Fingers crossed I'll play again on Sunday and have another good game hopefully."[LNB]Despite remaining realistic about his chances of playing in South Africa, the 21-year-old does admit he has better grounds for selection than he did before the previous campaign. [LNB]Then just 17 years old and without an Arsenal appearance to his name, the youngster was selected by coach Sven-Goran Eriksson for the tournament in Germany. [LNB]This time around, Walcott boasts an impressive record from the national side's qualifying campaign - peaking with a stunning hat-trick against Croatia. [LNB]"It's nice to actually get a chance to play and deserve to play as well," he added. [LNB]"I didn't deserve to be in the squad in 2006, when you're not playing in the Premier League it's not heard of at all.[LNB]"But I'm just trying to play well and concentrate on training well and if that comes hopefully I'll be in the squad but we'll see."