LONDON: Wayne Rooney has been warned about his future conduct following a remark the striker made to television cameras after Manchester United's defeat by Chelsea, the Football Association said on Monday.

Rooney appeared to mouth "12 men" to the cameras following Premier League champions United's 1-0 loss to leaders Chelsea on Sunday, a remark implying referee Martin Atkinson had been biased in favor of the Blues.

An FA spokesman said on Monday: "Wayne Rooney has been warned as to his future conduct following remarks made yesterday (Sunday)."