The Saints captain was an influential figure in tonight’s 1-0 win against Denmark, setting up Daniel Sturridge’s winner.
Lallana came off the bench in the second half at Wembley and posed a puzzle that the visitors could not solve.
The midfielder looks as though he will be heading to Brazil this summer, but he insists there is no complacency on his part.
“I’ve just got to keep working hard,” he said.
“The carrot’s there for everyone to see, for all the lads here.
“There’s probably going to be injuries, there’s going to be disappointment along the way, but as long as I give it my all that’s all I can do.”
Lallana added: “Nothing’s guaranteed. It’s been proven over the last couple of years that’s the case.
“If anything, I’ve got to work even harder now, as Shawy has, Jay-Rod and Rickie, and we’ll see what happens at the end of the season.”
Lallana’s appearance tonight meant a third international cap, but this was a first victory for the 25-year-old, having been on the losing side in his initial two England appearances.
“I’m delighted, most of all really because last time out we had two defeats, against Chile and Germany, so it was great to be involved in a winning England display,” he said.
“I just gave my best and that’s all you can do, as everyone else does.
“We know it’s the last time that we meet up before [Roy Hodgson] names his 30-man squad at the end of the season.
“There’s still ten really important club games, not just for ourselves, but for our clubs as well, so I’ll be concentrating on that now; getting back to the club, keeping fit, in good form, and hopefully get three points at Palace at the weekend.”
Discussing his role in the goal, Lallana said: “I just remember it was a corner, which we took short, and I think I cut back on my left, just stood it up, and Sturridge does what he does best – put the ball away.”
Lallana was full of praise for his teammate, Luke Shaw, who produced an impressive display at left-back in the second half, as he bids to beat Ashley Cole to a place in the World Cup squad.
“He’s been absolutely tremendous,” he said. “It was there for everyone to see how relaxed and calm he was, how level-headed and how comfortable he looked out there.
“But he knows he’s got a lot of work to do again.
“There’s two hugely-talented experienced players ahead of him, and they were great with him this week in making him settle, and it was a special evening for him today.”
Lallana added: “It’s outstanding to see. He came on today and showed the world really how confident and calm he is, and what an exceptionally talented left-back he is.
“That will be the first of many international caps.
“When Rooney and Gerrard and the likes of them compliment him there’s not much really for me to say.
“I had a word with him before he went on and told him to get his first pass off.
“What a great gesture it was that Gerrard gave him the ball straight away and gave him that first touch, because, at the end of the day, he’s only 18, he’s a kid still and it was a big thing tonight him playing.”