Chelsea striker Diego Costa could face disciplinary action after an apparent kick to the ribs of Liverpool defender Martin Skrtel seemingly went unseen by officials.

The Spaniard clashed with Skrtel at the half-way line, fouling the centre-back before being pulled down by Skrtel.

However, as they fell, Costa seemed to kick his heel into the ribs of the Slovakian..

Although referee Mark Clattenburg gave a foul for Costa's trip, he didn't take any action for the kick - although it is not yet clear if that is because he didn't see it or didn't deem it worthy of extra attention.

Clattenburg had a word with Costa immediately after to calm the striker.

Former referee Howard Webb, during his analysis for BT Sport, called the kick "violent" and a "clear red card.

"They [The FA] will have a look I think," he said. "I think it is a clear red card. He commits a foul on Martin Skrtel, then there is a little kick.

Chelsea vs Liverpool player ratings Show all 24 1 /24 Chelsea vs Liverpool player ratings Chelsea vs Liverpool player ratings CHELSEA: Asmir Begovic - 6 out of 10 Made several fine stops to deny Liverpool but couldn’t prevent Coutinho’s superb effort from squeezing past him just before the break. Was let down by his defence for the visitors’ two second-half goals. 2015 Getty Images Chelsea vs Liverpool player ratings Kurt Zouma - 5 out of 10 Did well to stop the threat of Lallana and Moreno on the left flank in the first half - putting his body on the line to prevent Lucas’ near-post header from going in - but began to be put under more pressure from Coutinho in the second period and began to struggle at right back. 2015 Catherine Ivill - AMA Chelsea vs Liverpool player ratings Cesar Azpilicueta - 7 out of 10 Set up Ramires’ opener with a superb cross that came after he had outrun Milner. Had his work cut out with Clyne regularly pushing forwards but defended well enough. 2015 Getty Images Chelsea vs Liverpool player ratings Gary Cahill - 5 out of 10 Combined well with Terry to protect Begovic and stop the threat of Firmino in the first half but should have done more to close in on Coutinho and Benteke when they went for goal in the second. 2015 Getty Images Chelsea vs Liverpool player ratings John Terry - 4 out of 10 The Chelsea captain was back to his best against the Reds with some solid defending in the first half, but then let himself down when he didn’t do enough to stop Coutinho from his getting his shot at goal before allowing Benteke the space and time to fire in Liverpool’s third goal. 2015 Getty Images Chelsea vs Liverpool player ratings Ramires - 7 out of 10 Headed in Chelsea’s opener to give the home side the lead, but was beaten too easily by Coutinho in the build-up to Liverpool’s equaliser and should have done more to close him down. Chelsea vs Liverpool player ratings John Obi Mikel - 6 out of 10 Helped provide cover for Chelsea’s defence in the first half, but was later brought off after picking up a yellow card. 2015 Getty Images Chelsea vs Liverpool player ratings Oscar - 5 out of 10 Spent the first half largely on the left flank and while he didn’t get involved in Chelsea’s attacking play as much, he did his job at helping to keep Milner at bay while dealing with Clyne’s runs forwards. But the second half saw him struggle to replicate his first-half showing with Liverpool pressing well. Chelsea vs Liverpool player ratings Willian - 6 out of 10 Was so often the driving force of Chelsea’s attacking play with his pace and tricky runs but had less of an impact in the second period. 2015 Getty Images Chelsea vs Liverpool player ratings Eden Hazard - 4 out of 10 Played largely down the middle and despite a bright start, saw his impact wane and was eventually brought off in the 58th minute for Kenedy. 2015 Getty Images Chelsea vs Liverpool player ratings Diego Costa - 5 out of 10 Was controlled by Skrtel and Sakho throughout the game and rarely proved a threat for the home side. He did well to head the ball off the line in second half but disappointed up front for Chelsea. 2015 Getty Images Chelsea vs Liverpool player ratings From the bench: Kenedy - 5 out of 10 Within seconds of coming on, he threatened to score but hit his shot into the side netting. Didn't do much else of note GETTY IMAGES Chelsea vs Liverpool player ratings LIVERPOOL: Simon Mignolet - 6 out of 10 May feel he could have done more to keep out Ramires’ opener but dealt with the rest of his tests well. 2015 AMA Sports Photo Agency Chelsea vs Liverpool player ratings Nathaniel Clyne - 7 out of 10 Was one of Liverpool’s best sources of attacking play in the first half down the right flank, and was unlucky not to have been given a first-half penalty when his shot hit Terry’s arm. Defended well at right-back and was one of Liverpool’s best players on the pitch. 2015 AMA Sports Photo Agency Chelsea vs Liverpool player ratings Martin Skrtel - 6 out of 10 llowed Azpilicueta to get his shot in to set up Ramires for the opener but, aside from that mistake, was superb to ensure Costa did not prove a threat for the home side. 2015 Liverpool FC Chelsea vs Liverpool player ratings Mamadou Sakho - 7 out of 10 Like Skrtel, the centre-back used his physical presence to shackle Costa throughout the game. 2015 Getty Images Chelsea vs Liverpool player ratings Alberto Moreno - 7 out of 10 Was outmuscled by Ramires in build-up to opener and will feel he could have done better, but he defended well at left-back while nearly getting a shot at goal in the second half following a fine run forwards. 2015 Liverpool FC Chelsea vs Liverpool player ratings Lucas Leiva - 7 out of 10 Received a yellow for a challenge on Mikel, but the Brazilian worked tirelessly in the middle of the park to snuff out attacks and try and create some for the visitors. Saw an effort at goal cleared by Begovic. 2015 Getty Images Chelsea vs Liverpool player ratings Emre Can - 6 out of 10 Looked frustrated by not being able to control the game in the first half and found himself escaping a yellow although he eventually got one for pulling back Willian. Despite an up-and-down first period marked by some sloppy passing, the midfielder came out from the break in better form and worked hard to keep a lid on the likes of Hazard and Willian. 2015 Getty Images Chelsea vs Liverpool player ratings James Milner - 6 out of 10 Should have done more to stop Azpilicueta from getting past him and setting up Ramires for the opening goal, but he grew into the game and began giving Chelsea problems with his forays forwards. 2015 Getty Images Chelsea vs Liverpool player ratings Adam Lallana - 6 out of 10 Tested Begovic with a few shots in the first half with his pace proving crucial in helping the visitors build up attacks from the right flank and also carried out his defensive duties well – making a superb clearance to deny Zouma in the second half. 2015 Getty Images Chelsea vs Liverpool player ratings Philippe Coutinho - 9 out of 10 Scored both of Liverpool’s goals –the first after weaving his way into space and getting past Ramires to net a brilliant solo effort before then scoring the winner in the 73rd minute. Was Liverpool’s star man. 2015 Getty Images Chelsea vs Liverpool player ratings Roberto Firmino - 7 out of 10 After a relatively quiet opening period in which he kept dropping deep to try and find the ball, the forward provided the assist for Coutinho’s opener in the dying seconds of the first half. He was brought off for Benteke in the latter stages of the game, but Klopp will see the Brazilian’s showing as positive going forwards. 2015 Liverpool FC Chelsea vs Liverpool player ratings From the bench: Christian Benteke - 8 out of 10 Secured the win with his well-taken goal from Ibe’s cross after being brought on as a second-half substitute. Proved the impact change from Klopp.

"The second action is a clear act of violent conduct. Mark Clattenburg is pretty close and is in a good position and it's difficult to say that he hasn't seen this.

"Normally the FA won't take action when the ref is looking at it. But just because he is looking in that direction it doesn't mean he is focussed on that act of violence, and he can't have been because he didn't see the kick and didn't give a red card.

"I doubt that the FA will take action because Mark is looking in that direction and it is not off the ball. But it is a clear red card and Diego Costa is a lucky boy on that occasion."