Hong Kong champion Able Friend's career is in the balance with the horse to be sidelined for at least six months with a rare tendon injury.

Trainer John Moore said he would recommend Able Friend be sent to Australia for his rehabilitation.

Formerly trained by Hawkes Racing in Sydney, Able Friend is Hong Kong's highest rated horse but was below par when third in the International Mile last month.

MRI scans this week revealed a strained deep digital flexor tendon in his right front foot.

"He is done for the season," Moore told the South China Morning Post.

"He went into the Hong Kong Mile with a bruised sole. We kept him in minor work and the problem didn't resolve itself. We got the scans back, got the bad news and now we have to put him aside.

"It's very disappointing to have one of the top five horses in the world and to have him sidelined.

"I'll be asking the owner (Dr Cornel Li Fook-kwan) if we can send him offshore and find the best place to rehab him."