Lallana has featured just 12 times for Liverpool in 2017-18, after seeing his season disrupted by a series of muscular injuries.
Now he is determined to finish a difficult term on a high and in the process play himself into contention for the World Cup.
"I’m fully fit now. I had to manage myself probably for the first couple of days. Hence why I wasn’t involved over in Holland. But it’s been a great end to the week personally," he explained to reporters on Tuesday.
"It’s great to be back out there in an England shirt for the first time this season since last summer.
"I’m confident enough in my own ability and what I bring to the squad. I’m smart enough not to be complacent and to know that there’s plenty of talented players that want to make the squad, even lads who aren’t here today.
"I’ll go back to my club now, we’ve got Palace at the weekend then [Manchester] City, then the Merseyside derby, then City. So it doesn’t stop. Straight back into it tomorrow at Melwood and just keep ticking over and look to get that rhythm.
"At any level I’m not built with complacency. I think you see that in the way I play. The people that manage me know that, my teammates know that. I’m not built like that."
While Lallana admitted that his chances of making the cut for Russia have been hurt by injury, he still holds out hope – while affirming he never allowed himself to dwell on his fitness issues.
"To get that rhythm you just need minutes on the pitch. It’s not just about training, it’s about playing competitive football. And there’s plenty of time between now and the end of the season. I think the assistant said to me one of the World Cups Darren Anderton hadn’t played a competitive game until the 11th of April so that just shows you," he said.
"I’m not one that sulks when he’s injured. I use it as time to learn, to pick up on things. So I studied all the England games, every one they played, I watched them closely, the Brazil, the Germany game when we changed the system, thinking when I’m back fit where do I see myself playing in that system.
"Me and the boss [Gareth Southgate] have got a great relationship. We’ve been speaking frequently throughout the season. He’s been interested to know where I’ve been on my rehab. I’ve been down to St George’s Park a couple of times. I suppose that’s where the confidence comes from.
"He recognises what I bring to the team. My teammates recognise that and I recognise that. So although I’ve been injured, these things happen. I feel I’m physically and mentally as fresh as anyone going into the backend of the season and for the World Cup."