Petrov won a long, gruelling battle with leukaemia.

They know better than most the toll that takes on families.

Between them, Martin O’Neill, once their manager at Parkhead, paid tribute to both men’s courage.

“The two young men beside me had those experiences. John and Stiliyan have fought incredible battles. I’ve got the utmost regard for them as people. Their battles were excruciatingly difficult and they fought them with great courage and determination. Their efforts were just fantastic and that’s the reason they are here today, the incredible courage they showed.”

Hartson has spoken before about walking around for four years with a lump, too afraid to get it checked.

He has raised awareness and urged young men, however fit, to face up to their health concerns. He knows well too that courage and fight bring no guarantees and his thoughts were for a man and a family who didn’t get the reprieve he and his did.

“When I heard Liam was going through an illness, I managed to speak to him a few weeks before he passed away.

“He sounded ready for the challenge. He knew he had a fight on his hands and then, sadly, I got the call to say that he had passed.

“Cancer, it doesn’t discriminate. Anybody can get cancer at any time and it was one of those very unfortunate illnesses that has taken another young man.”

Petrov is a regular now at occasions like this, touched by the support the football community showed him and his family.

“We’re here because Liam was a friend first, teammate after. It’s about supporting his family.

“We are going to show them how good Liam was, not only as a player, but as a human being as well.

“I do a lot of charity games. I know how hard it is to go through a cancer battle. Me and John did it. We know it doesn’t just affect people who fight with it, but the people around them as well.

“It’s a sellout, a great venue. We are going to show people who fight cancer and the people out there who support them, we will show we are beside them in their battles.”

Hartson recalled the young Miller at Parkhead, invited across from the youth ranks on Fridays to join the senior pros.

“Straight away, you could tell he was very comfortable in that environment at the higher level and he played in some very big games for us. I would have obviously loved to have played with him a little bit longer, but no disrespect to Martin, when Alex Ferguson phones you up, a man of his calibre, it’s was very difficult for Liam to turn Manchester United down,” he said.

“He was quite unassuming. He was very quiet, but he did his talking on the pitch. It’s a real honour to have been asked to come over to play my own respects to him on a wonderful occasion. It’s a celebration of Liam’s life and that’s how it should be seen.”