Officials behind each goal would help stop grappling in the Premier League... it's impossible for a referee to see everything as I learned at Stamford Bridge

Meticulous preparation helped Pierluigi Collina become one of the finest referees we have seen in football.

And he had certainly done his homework before Chelsea's Champions League encounter with Barcelona at Stamford Bridge in 2005.

'I knew that at corners everything was done by Chelsea to help John Terry head the ball,' says the Italian in an interview prompted by Sportsmail's campaign to put a stop to wrestling in the penalty area. 'Blocking. Certain tactics. My focus had to be around Terry.'

In the 76th minute of the second leg of a tense last-16 tie, Chelsea earned what proved the all-important corner. The score was 4-4 on aggregate, with the Catalans set to advance on the away-goals rule. As Damien Duff delivered the ball, Collina had those legendary piercing eyes fixed on Chelsea's captain.

Chelsea defender John Terry (left) rises highest to score a header against Barcelona in March, 2005

Terry's team-mate Ricardo Carvalho (second from right) had pushed over Barca keeper Victor Valdes

Barca's players appealed to referee Pierluigi Collina but the Italian official allowed Terry's goal to stand

'What I saw was the opponent almost handle the ball in trying to stop Terry — and I saw Terry head the ball cleanly and the ball then finish in the net,' he says. 'I gave the goal and I felt confident I had achieved the correct result. But afterwards, when I watched the video of the game, I realised that what I had completely missed was contact between Ricardo Carvalho and the Barcelona goalkeeper, Victor Valdes. Had I seen that, the goal would not have been given. But it was impossible for me to see something so far away from where I felt my focus needed to be.'

Collina recalls this story to illustrate a point after agreeing to join the debate raging in the English game following a spate of high-profile incidents in the Barclays Premier League.

Led by Sportsmail's Hands Off In The Box campaign, which Collina has been following, there is now a desire among senior English referees and members of the Premier League hierarchy to tackle those masters of the dark arts.

Collina believes extra officials can be a big help

Collina does not wish to interfere in what he respectfully recognises as 'a domestic issue'. But he will discuss, in his role as UEFA's chief refereeing officer, how the problem has been addressed by European football's governing body.

In Collina's opinion, the introduction of additional officials standing at the side of the goal has gone a long way to eradicating incidents of blocking and wrestling in the Champions and Europa Leagues. Such cheating was something he considered a serious problem, and he was a central figure in finding a solution.

'We introduced additional referees to the Europa League in 2009 and the Champions League in 2010, and we started to see these kinds of incidents less and less,' says Collina.

'Incidents can still occur. They can still be missed because, at the end of the day, we are talking about human beings here. But based on our experience this in no longer a major issue in UEFA competitions.

'My point with that Chelsea game is the fact that, as a referee, you will know which players are most likely to commit these kinds of offences. So with one pair of eyes that is the area you will attempt to concentrate on. You will do your best.

'But a second pair of eyes, in the form of an additional referee, gives you more control of the penalty area, which of course is where most of the important decisions in a game will be made.

'It isn't a perfect system but it is a good system and it works in two ways. Firstly because, of course, it is difficult for one person to see everything. He can focus on the most risky players but an additional referee, who communicates with the referee using a microphone, can see something more.

'I can tell you about Howard Webb, and two games he refereed — one at Euro 2012 and a Champions League semi-final game between Real Madrid and Bayern Munich last season.

'There were two decisions that were made based on what the additional referee had seen. We know this because we have listened to the conversations.'