Mike Dean has admitted he made a mistake by awarding West Bromwich Albion a penalty in their New Year's Eve clash with Arsenal, according to referees' chief Mike Riley.

Dean and his team of officials were confronted by Arsenal boss Arsene Wenger after Calum Chambers was penalised for a handball in the 88th minute of the 1-1 draw at The Hawthorns.

Wenger was subsequently handed a three-match touchline ban and a £40,000 fine but, on the eve of the introduction of Video Assistant Referee (VAR) technology to English football, it has emerged that Dean has accepted he got the decision wrong.

West Brom vs Arsenal player ratings Show all 23 1 /23 West Brom vs Arsenal player ratings West Brom vs Arsenal player ratings <b>West Brom:</b> Boaz Myhill – 7 out of 10 Left stranded for Giroud’s header as he was given no chance from close range. Otherwise commanded his area very well, and his good day’s work was summed up with a late save from Koscielny’s volley. 2015 Getty Images West Brom vs Arsenal player ratings Craig Dawson – 7 out of 10 Had his work cut out in the second half as Sanchez switched to the left. But he did well to reduce the threat from Gibbs and frustrated the Chilean forward late on. 2015 Getty Images West Brom vs Arsenal player ratings Jonny Evans – 7 out of 10 Showed his valuable experience as he stuck to Giroud in open play, giving the Frenchman no chance of getting a clear-cut effort on goal. West Brom vs Arsenal player ratings Jonas Olsson – 5 out of 10 At fault for Giroud’s opener as he lost his man at Özil’s free-kick. Guilty of messing around with the ball ahead of Arsenal’s penalty, though that may have had its desired effect on Cazorla. 2015 Getty Images West Brom vs Arsenal player ratings Chris Brunt – 7 out of 10 Perfect delivery gave Morrison the chance to score from his free-kick. Tried to get forward when possible, but today he knew his duty came in defence and he forced Bellerin to try and go outside him each time he attacked. 2015 Getty Images West Brom vs Arsenal player ratings James Morrison – 8 out of 10 Expertly finished with the outside of his right foot to volley home and level the scores from a Brunt free-kick. Worked his socks off to try and disrupt the Arsenal midfield axis, with a fair amount of success. 2015 Getty Images West Brom vs Arsenal player ratings Darren Fletcher – 6 out of 10 Sat quite deep to partner Yacob in shielding the back-four, although he didn’t have many stand-out moments. 2015 Getty Images West Brom vs Arsenal player ratings Claudio Yacob – 6 out of 10 Another who was fairly anonymous when it came to game-changing decisions, but he was always in position to cut out a killer ball and Tony Pulis could ask no more of him. 2015 Getty Images West Brom vs Arsenal player ratings James McClean – 8 out of 10 Fantastic run down the left before crossing into goal-mouth produced Arteta’s own-goal. He gave Bellerin plenty to think about as he drifted across the midfield at will. 2015 Getty Images West Brom vs Arsenal player ratings Stephane Sessegnon – 6 out of 10 Played in McClean for the second after committing Koscielny to pull Arsenal’s defence ragged. 2015 Getty Images West Brom vs Arsenal player ratings Solomon Rondon – 5 out of 10 Fairly anonymous and was hauled off for Saido Berahino in the second half. The England Under-21 striker looked much more of a threat. 2015 Getty Images West Brom vs Arsenal player ratings <b>Arsenal:</b> Petr Cech – 6 out of 10 Slightly off his line which allowed Morrison to volley the ball over his head, but there was little he could do for the second goal. Reaction save stopped a late Berahino effort although the whistle had already gone. 2015 Getty Images West Brom vs Arsenal player ratings Hector Bellerin – 6 out of 10 Lost Morrison for the goal as he was caught napping when the ball was airborne. Looked short on match fitness, although he was his ever keen self to work down the right in search of the equaliser. 2015 Getty Images West Brom vs Arsenal player ratings Laurent Koscielny – 5 out of 10 Still not his normal self and Wenger was right to question whether he should play him in the build-up to the match. Simple header back to Cech went for a corner, and he lost Berahino late on. 2015 The Arsenal Football Club Plc West Brom vs Arsenal player ratings Per Mertesacker – 5 out of 10 Went AWOL for the second goal which forced Arteta back into defence. Looked nervy on the ball, and still struggles to connect with attacking aerial balls. 2015 The Arsenal Football Club Plc West Brom vs Arsenal player ratings Nacho Monreal – 6 out of 10 The Spaniard didn’t press forward as much as he has recently with Gibbs in front of him sticking to the left, and that had an impact on Arsenal’s attacking threat as there were few overlaps from the left-back. Fairly solid in defence though, with little threat coming down his flank. 2015 The Arsenal Football Club Plc West Brom vs Arsenal player ratings Francis Coquelin – 5 out of 10 Lasted just 13 minutes after his own sliding tackle saw him suffer a knock to his knee. Replaced by Mikel Arteta, with disastrous consequences. 2015 Getty Images West Brom vs Arsenal player ratings Santi Cazorla – 4 out of 10 His form has deserted him recently. His passing was terrible in attacking positions, and his dreadful penalty attempt sums up Arsenal’s day. Slipped as he kicked the ball, sending it into his standing foot and over the bar. 2015 Getty Images West Brom vs Arsenal player ratings Alexis Sanchez – out of 10 Worked extremely hard but couldn’t fashion many chances for himself. One clear effort saw the ball escape his reach with the goal at his mercy. 2015 The Arsenal Football Club Plc West Brom vs Arsenal player ratings Mesut Ozil – 7 out of 10 Broke the record for consecutive assists as his floated free-kick saw Giroud head home to register a seventh straight game in which he’s set up a goal. Probed throughout and looked to be Arsenal’s creator for the equaliser – only it never came. 2015 Getty Images West Brom vs Arsenal player ratings Kieran Gibbs – 5 out of 10 Dangerous cross late in the first half went unpunished as no one in red could reach it. Not an out-and-out attacking player though and it showed, and he was replaced by Joel Campbell with half an hour to go. West Brom vs Arsenal player ratings Olivier Giroud – 6 out of 10 Emotion poured out of him before kick-off as La Marseillaise rang out, and he soon had something to shout about as he headed in Ozil’s free-kick. Booked late in the first half as Arsenal lost their way, and he faded in the second half. 2015 Getty Images West Brom vs Arsenal player ratings Mikel Arteta – 1 out of 10 Terrible introduction for injured Coquelin after 13 minutes in. Conceded the free-kick that led to Morrison’s goal – though he appeared to get a toe on the ball – before handling in an own-goal to give Baggies the lead. His nightmare outing was capped when he was injured three minutes after the break, and was replaced by Mathieu Flamini having played 36 minutes. 2015 Getty Images

Riley feels VAR, which will be used for the first time in England on Monday night when Brighton & Hove Albion host Crystal Palace in the FA Cup and again on Wednesday for Arsenal's clash with Chelsea in the Carabao Cup semi-finals, would have helped overturn the decision.

"You award the penalty because what you have seen on the pitch is the arm coming towards the ball," Riley said, quoted by the Daily Express.

"What is handball can look to you on the field of play if you get one look at it. But immediately there is evidence from another camera angle which shows actually the opposite happened. That is the safety net of the VAR.

"I think Chambers would have been overturned. The question you ask is, is it an act of deliberate handball? And the reverse angle shows him trying to bring his arm out of the way of the ball, rather than the reverse.

"I know Mike would have overturned it. He messages people, and he's a very honest guy, and he goes, 'I got it wrong'. He knows he did."

But Riley has expressed caution, warning VAR technology will not correct all of the injustices witnessed during matches.

Riley is encouraged by its potential but believes a period of scepticism surrounding it is inevitable, and that even when system flaws have been eradicated, imperfections will remain part of the game.

The referee of the Brighton v Palace game, Andre Marriner, will be remotely assisted on potentially game-changing decisions related to goals, penalties, straight red cards and cases of mistaken identity by Neil Swarbrick and Peter Kirkup.

Wenger was handed a three-game touchline ban and fined £40,000 (Getty)

Attempts to minimise disruption to the game means Marriner's decisions can only be changed if a video review demonstrates he has made a clear error. Even then it is only if he requests assistance or it is recommended by the VAR, and Marriner makes the final decision.

Players risk a booking if they attempt to influence any official to use VAR and managers or other non-playing club staff risk being sent to the stand if they do the same, or encroach on the area where the referee is reviewing footage.

"This will be really good for football, when we've worked through it, when we've ironed out all the subtleties in the protocol," said Riley, the managing director of Professional Game Match Officials Limited (PGMOL).

Mike Dean awarded a controversial penalty against Arsenal that he has since admitted was a mistake (Getty)

"It's going to take us time. You're actually asking a generation of referees to relearn or learn new processes and skills.

"It will never be 100 per cent (perfect) because it's so subjective on certain things and we're asking the clear and obvious question.

"We don't want errors. If through this we make that four per cent (of incorrect decisions made by select referees) two per cent, we've benefited the game.

"This is a starting point. You're balancing all the time: 'Let's not re-referee the game; let's keep the flow' versus 'Let's get the key situations right'."