As the players filed out to a packed Celtic Park and a rousing rendition of You’ll Never Walk Alone echoed throughout the stadium, the camera focused on Nancy.
The disco lights, which were turned on profusely on these European nights, were directed towards the Frenchman.
Hart said the ground in Glasgow’s east end is a “special place” on such occasions, but the atmosphere there has turned sour in recent times.
Long before Nancy’s arrival, the club was riven by discord.
The events of last summer – recruitment problems, dismay in the Champions League, the acrimonious exit of Brendan Rodgers – had cast a long shadow.
Martin O’Neill’s interim spell at the club stabilized things, with seven wins from eight games and an improvement in morale.
But when Roma had a fourth goal disallowed in the final minutes on Thursday, much of the crowd had gone home. Many fans had seen enough.
“It breaks my heart to see [Celtic Park] like that,” Hart said. “The atmosphere just isn’t there. This is a very special football club, but it is only special when it is united.
“It’s not easy for a new manager and a new system, but it’s not rocket science and Nancy has to learn quickly.”
Perhaps one thing all Green and White sectors could agree on is that Roma were on a rampage as they galloped to a second victory in Glasgow this season.
“It wasn’t good enough, especially in the first half, we lost too many duels and too many careless balls,” said midfielder Arne Engels, who missed a penalty in the first half.
“We know we can do better and hopefully we can keep going because we have a final in a few days. We need to keep our heads up and keep going.”
“It’s up to us to react. We need to look at ourselves to continue acting.”
