The 25-year-old Liverpool midfielder has played for neither club nor country since sustaining multiple ligament damage in a Champions League quarter-final against Roma last April.
He was widely touted to be a key component of Gareth Southgate's World Cup squad. Oxlade-Chamberlain spoke to 'Sky Sports' about how hard he found watching the tournament from home.
"I can't sit here and lie and say it was easy. It was really difficult," he said.
"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."