Adam Lallana has admitted that it was "frustrating" to miss out on a spot in the England squad for the 2018 World Cup, but the Liverpool midfielder has vowed to return stronger from his injury woes.

Lallana only made 13 appearances for Liverpool last term due to injury, and was ultimately left out of Gareth Southgate's squad for the tournament in Russia after failing to recover from a hamstring problem.

The 30-year-old, however, is confident that he can still contribute in a big way for the national team moving forward.

"Of course it was frustrating to miss out because I wanted to be there. Sometimes when you are a professional footballer, you have to deal with tough decisions," The Telegraph quotes Lallana as saying.

"It probably wasn't a comfortable call for [Southgate] but he made it, like he made it for the other lads who missed out. I know that if my season was different and I had been fit, I would have been there. But it was probably the right call. Gareth has been absolutely brilliant.

"He said you don't gain your form in a tournament, going on history and past experiences. The lads had a massive tournament but I am sure I have still got a lot to give. I will be there in the next camp.

"I still feel that is the case. If I had been fit and had a half decent season in terms of availability, there is no shadow of a doubt that I would have been at the World Cup. But I had a disappointing season in terms of my fitness and, you know, it just wasn't meant to be. Last season was so stop-start that it was more or less written off."

Lallana, who started Liverpool's 3-1 defeat to Borussia Dortmund on July 22, has scored three times in 34 appearances for the Three Lions.