The Southampton skipper turned in a Man of the Match performance as he inspired their 4-1 win over Hull City at the weekend.
Lallana's display came in front of England boss Roy Hodgson, who days earlier had named Lallana in his squad to face Chile and Germany, along with team-mates Rickie Lambert and Jay Rodriguez.
"I just want to keep my feet on the ground and keep working hard," said Lallana.
''I want to enjoy my time away with England and hopefully, if I get some minutes, try to impress.''
The 25-year-old insisted that he did not really take much notice of the fact that Hodgson was present.
''Someone did mention Roy was in the crowd but it is one of those things you have to try and put to the back of your mind and concentrate on your job,'' Lallana, an unused England substitute against Ukraine last year, said.
''Every time I play I just want to go on to the pitch and enjoy my football and play to the best of my ability, help the team get three points.
''I feel like I am playing with freedom and confidence at the minute, as the team is, and that is one of the main reasons why we are getting these good results.''
Lallana admits it has been one of the biggest weeks of his life.
''It has been an emotional week, a very proud week for my family,'' Lallana said.
''It has been a proud week for the club as well, with J-Rod and Rickie also being named in the squad.
''It just proves how far the club has come forward and it is credit to not just the players, but the management staff, chairman, the scouting and recruitment department, and the fans, who have stuck with us when we were in League One not so long ago.
''We are happy with the way things are going and we just want to keep performing well.
''Our next game is Arsenal at the Emirates and it doesn't get much tougher than that.''