The Auxerre striker, 20, broke his leg twice in 2010 and has since admitted that the injury made him consider his professional future.
"At that time, I was all alone. You say to yourself: 'But I can't even run'. I said to myself it was finished. I had made a lot of sacrifices," the Daily Mail quotes him as saying.
"I started playing football at six, arrived at Auxerre at 13, and overnight I couldn't run any more. You turn in on yourself, and start to think about doing other jobs.
"One day I said to myself: 'I'm going to push as hard as I can. If it goes, it goes'."
Sanogo is expected to arrive at the Emirates Stadium before the start of the new Premier League campaign.