Samoan-born Tuilagi, who will start Saturday's game at outside centre, said: "There is a lot of competition for places and I just want to take this chance and do the best I can for the team.
"The boys have worked hard during the camp but now we have to perform against Wales."
England manager Martin Johnson said of the 20-year-old: "He played some very good rugby last year in a tough Premiership and in Europe, so we are looking forward to seeing him play."
Prop Matt Stevens is also making a return to the squad for the first time since 2008 after serving a two-year ban for testing positive for cocaine in January 2009.
"Matt [Stevens] is a very smart player, obviously he can do the work in the tight phases but he is a very smart rugby player as well. Having those [attributes] on the field in those positions is very important so it is a good opportunity for him," Johnson added.
Johnson must finalise his 30-man squad for autumn's World Cup in New Zealand by August 22.