Liverpool midfielder Alex Oxlade-Chamberlain has conceded that "it was really difficult" to miss out on the 2018 World Cup due to a serious knee problem.

Oxlade-Chamberlain is expected to miss the majority of the 2018-19 campaign as he builds back to fitness.

Indeed, the 25-year-old seriously damaged his knee during Liverpool's Champions League semi-final first leg against Roma in late April, and underwent surgery to repair the issue at the start of May.

The midfielder missed the 2018 Champions League final in addition to the World Cup, and he has admitted that it was "not easy" despite being excited by England's performances en route to the semi-finals.

"I can't sit here and lie and say it was easy. It was really difficult," Oxlade-Chamberlain told Sky Sports News. "Obviously I had a realistic chance to be playing and definitely to be there, so that was obviously not easy.

"But at the same time I went into England fan mode. You can't not get excited. As the games were going on and I was seeing a lot of my friends out there doing so well, it was great to see. I was so excited for them and I got fully into the spirit. I was gutted at the end when we got so close."

Oxlade-Chamberlain also said that he was "progressing" in his injury recovery.