Marcos Alonso faces the threat of missing Chelsea’s FA Cup semi-final as the FA disciplinary chiefs examine footage of his challenge on Southampton’s Shane Long.

Alonso was not penalised for a foul at the time by referee Mike Dean but could receive a retrospective three match ban for violent conduct with a decision expected to be made on Tuesday.

It would rule him out of Premier League games at Burnley and Swansea, either side of the FA Cup semi-final against Southampton, at Wembley on Sunday.

Marcos Alonso appeared to stamp on the calf of Shane Long at Southampton on Saturday

Dean was labelled a joke and an embarrassment by Sky Sports pundits Matt Le Tissier and Dennis Wise after appearing to ignore Alonso's stamp on Lon.

Southampton led Chelsea 1-0 in the first-half at St Mary's when, shortly before the break, Alonso trod on the back of Long's leg, pressing his studs into the forward's right calf.

The challenge went unpunished, however, and at half-time former Saint Le Tissier attacked Dean's decision.

The situation then became fractious as Alonso charged in in an attempt to win possession

Long battled for the ball with Cesc Fabregas in the middle of the St Mary's pitch

'How this is not seen by the referee is quite bizarre,' Le Tissier told Sky Sports. 'If he wasn’t quite so arrogant he’d probably be embarrassed about missing a tackle like this.

'There is one thing in his mind there, and that is to hurt Shane Long and Mike Dean is looking right at the incident. How on earth he misses this is incredible.'

Dean appeared to have seen the coming together, which saw two Southampton and two Chelsea players battle for the ball in the middle of the pitch.

Willian eventually came out with the ball with Long left on the floor clutching his leg in pain as the Blues continued their attack and refused to halt the game.