Gameiro confirms ACL injury via Twitter
Gameiro underwent scans on Saturday, which confirmed the extent of the injury. He will undergo surgery next week.
It's a cruel blow for the 22-year-old who suffered the same season-ending injury 12 months ago while with the Olyroos.
Gameiro tweeted that he was "devastated and torn to bits" by the injury, but vowed to be back better and stronger.
City coach John van’t Schip said; "We are of course very disappointed to learn of the extent of Corey’s injury, particularly after his hard work and rehabilitation with us, and his work to come back to fitness.
“Corey is no doubt devastated with the news and our thoughts are with him during this difficult period.”
— Corey Gameiro (@CoreyGameiro) November 28, 2015