Liverpool man Sturridge scored a stunning opener in England's 3-0 friendly win over Peru last Friday as Roy Hodgson's men continued their preparations for the tournament, which starts in 10 days' time in Brazil.
That strike marked Sturridge's fourth goal in his last seven international appearances and came after a club campaign that saw him net 24 goals in all competitions.
For all his proficiency in front of goal, the former Chelsea and Manchester City player insists he cannot take his prospective place in Hodgson's team for granted.
Sturridge said: "There are obviously certain players who have their spots nailed down but, in my mind, I haven't and I am working hard every day to continue to show what I can do.
"For me, there are no guarantees in football and for me I will just work hard and not worry about which team the manager will pick.
"I will focus on what I can for the team and leave the decisions to the boss because that is what he does.
"To be honest, I really haven't put much thought into the goal against Peru. It's gone now. I'm not revelling in it, I'm not worrying about it. It's about the team, it's not about myself.
"I don't mind if I score or not because come Italy it's going to be a big game and it's not really about now."
England are set to prepare for the hot conditions of Brazil with final warm-up games against Ecuador and Honduras in Miami, before taking on Italy in their opening game on June 14 in Manaus.
Hodgson's side are arguably viewed as underdogs in a group that also contains Uruguay and Costa Rica, but Sturridge feels England have the quality in the squad to make an impression.
"I think everyone is desperate to show what they can do and desperate to bring some success," he added.
"We understand the magnitude of the task and it is a big task to go to a World Cup and have success, for every country, not just us.
"We have got a great squad and whatever happens out there we just look to put in good performances that we can be proud of."
