The Football Association are investigating a claim of mistaken identity over Watford defender Danny Shittu's yellow card against Sheffield United on Saturday.

Shittu was booked by referee Martin Atkinson in the 34th minute after Blades striker Jon Stead was felled as he looked to break through.

But it was defensive partner Clarke Carlisle, not Shittu, who committed the foul, with the former Leeds defender lucky to escape a red card having already been booked for trying to kick the ball out of goalkeeper Paddy Kenny's hands in the 18th minute.

The FA have confirmed the request was put forward by the Hornets following their 1-0 defeat at Bramall Lane.

If the claim is upheld, sanctions against Shittu would be transferred to fellow centre-back Carlisle meaning the defender would face a suspension.