A leg injury has forced the withdrawal from Thursday's Gr.1 Barfoot & Thompson Auckland Cup of the defending champion El Soldado.

"He's done something to his sesamoid joint or ligament and unfortunately there's been no improvement," part-owner and trainer Phillip Devcich said.

"Whether we retire him or not I don't know, he'll be 11 next season, but he has been a fantastic horse and when he's won, he's won in style."

El Soldado has won eight races with his most recent success a front-running victory in the Gr.2 Avondale Cup.