Was Steven Gerrard's red card Brendan Rodgers' fault?
The Liverpool captain was desperate to make an impact when he came off the substitutes bench at Anfield after the break.
In his 17-year, 700-appearance career at Liverpool, Gerrard has never not been first-choice - in fact he's been the first name on the team sheet for the majority of his career.
Despite his injury in recent weeks, the form of Brendan Rodgers' team in his absence and Gerrard's own struggles this season, it was still a surprise to see a player of his stature and experience left out of the team for a potential Champions League decider against fierce rivals Manchester United.
Perhaps he was expecting a stronger tackle as retribution from Herrera but he reacts, despite barely being touched, by stamping on the Spaniard.
The 38-second cameo showed beyond doubt that Gerrard wanted to be Liverpool's hero in the second half. He immediately wanted to up the tempo and the long pass and tackle on Mata got huge cheers from the home crowd - who had been in a slumber for most of the first 45 minutes as United dominated possession.
Gerrard was playing on the edge, but became caught up in the emotion of his last game against Manchester United. He was so desperate to win that he went beyond the edge and lost control.
Gerrard has always been a player who plays with emotion - his best moments in red have come through sheer inspiration - but he has not always been able to control it.
The sending off now means that four of Gerrard's seven red cards have been shown against Liverpool's two biggest rivals, Manchester United and Everton (two each).
Sky Sports pundit and long-time Liverpool team-mate Jamie Carragher summed up exactly what was going through Gerrard's head.
"It was a moment of madness. There’s no doubt - there would be frustration," Carragher said after the game.
"He's always been the man, the captain. There’s never been a case where he’s been out of the team and as soon as he’s fit he goes straight back in the team. "Watching the first time from the bench, he’d have been disappointed. Liverpool weren’t playing well, they were losing but I think he’d have been watching players in his position, performing not great, and thinking: ‘Why am I not playing? Why am I not on that pitch?’
"Steven Gerrard is an emotional player - you see that in his career. He’s taken teams I’ve played in into some unbelievable moments. There’s no doubt being a local player, the emotion of these occasions, the frustration coming into this game, has contributed to the moment of madness."
Carragher added: "He wouldn’t have wanted it to end like this. He’s still got five or six games. From the club’s point of view firstly, but from his point of view, I’d love to see Liverpool get in the FA Cup final for him."
It's easy to lay the blame at the door of the manager for not starting Gerrard but there was sound tactical sense in leaving him out.
Now 34, Gerrard has not been anywhere close to his best this season, in fact one might argue that it has been his worst in a Liverpool shirt.
After forming a telepathic partnership with Luis Suarez last season - where he got Premier League high 13 assists, as well as 13 goals - this season Gerrard has just one assist (he has six goals) in his 24 matches.
Part of the reason that Rodgers dropped his 4-2-3-1 formation and switched to a 4-3-3 was because the Reds were too ponderous in the middle and attacking thirds.
During his time out with injury Liverpool played seven games and lost just once, Besiktas in the Europa League, picking up superb wins against Southampton and Manchester City along the way - Joe Allen was excellent during that run and Rodgers reasoned that he deserved to keep his starting place over Gerrard.
It's too simple to say Rodgers is to blame for the red card for leaving Gerrard out, the midfielder has to take blame for his own actions and took "full responsibility" in apologising last night.
But it does seem like Rodgers made a mistake leaving one of Liverpool's greatest ever players on the bench for a game of this magnitude.
Belfast Telegraph Digital