The 19-year-old left the Saints in 2011 to join Arsenal for an initial fee of £12m.
Oxlade-Chamberlain has also said that he is very grateful to his former club, despite them nearly allowing his to leave at age 13. Instead of releasing him, the club decided to hold him back in the Under-14s so that he could develop.
"Southampton were going to release me then," the England international told The Times.
"They said I was not big enough. It was just because I hadn't grown.
"They said I couldn't cope but they said that I was technically one of the best players, so instead they were going to keep me in the Under-14s. I played there for one season."
Oxlade-Chamberlain has scored five goals in 30 domestic games for the Gunners.