The midfielder impressed on his debut for Roy Hodgson's side in the defeat to Chile last month and his form for the Saints so far this term has put him in contention for the place on the play to Brazil.
Should that be the case Lallana and his fiance Emily Jubb will have to re-arrange their June 14 wedding, with England due to face Italy in their opening match of the tournament on the same day.
"Yes, the wedding is on June 14," Lallana said in The Sun.
"My fiance and I see it as a nice problem to have. Not many people can say they have played in the World Cup so it's a no-brainer really for anyone.
"Of course we have spoken about it. She is very laid back and I am very laid back with it all. It was all arranged a while ago before I was called up."