The Italian midfielder remembers his time in Glasgow as probably the finest experience of his playing career, with the supporters, the atmosphere and the character of the Scottish game leaving an impression that has stayed with him long after he departed.
Donati arrived at Celtic from AC Milan in the summer of 2007, signing a four-year contract under Gordon Strachan. He spent two seasons at the club, experiencing Champions League football and helping Celtic qualify for the last 16 of the competition in 2007-08.
It was a period he looks back on with enormous affection. Asked to describe the highlights of his playing career, Donati immediately included his time at Celtic among the experiences that meant the most to him.
He told Football Presse, “The good moments were, as I said at the beginning, Atalanta, and then Celtic, where I played in the Champions League. That was an incredible period, a beautiful one.
“It was a fantastic experience, probably the most beautiful of my footballing life, because I felt comfortable there. I found myself among a genuine, authentic people, in a fantastic stadium. Celtic Park, especially on European nights, is something magical.
“And I am not just saying that myself. You hear the same thing from great players who have gone there as opponents. For me, it was a fantastic experience, a beautiful one.”
It is the atmosphere at Celtic Park that remains particularly prominent in his memories. Donati had played in Italy for clubs including AC Milan and Atalanta, but his experience in Glasgow gave him an appreciation of a different kind of football culture.
The relationship between the club and its supporters was central to that experience. His description of the Celtic support is strikingly simple, but it captures what he believes made his time in Scotland so special: authenticity.
He also makes clear that his affection for Scotland was not confined to his time at Celtic. His subsequent experiences with Hamilton Academical and St Mirren as a player, followed by his coaching work at Kilmarnock, gave him a broader understanding of the country and its football.
“But it wasn't only Celtic. I also played for Hamilton, I spent a short time at St Mirren, and I coached at Kilmarnock. Scotland is a country I like because of the purity people have in the way they approach life and the way they approach football.
“If you look at football today, there is a lot of what I would call acting on the pitch. Players throw themselves to the ground, make a scene, stay down and look for VAR. Unfortunately, that is how things are now, but it isn't beautiful.
“Over there, that doesn't exist, or it is very minimal.”
It is an observation that helps explain why Donati's memories of Celtic and Scottish football remain so positive. He is not simply talking about the spectacle of a European evening or the size of the crowd. He is describing a culture in which he felt the approach to the game retained something genuine.
That appreciation also informs his assessment of the Scottish players increasingly making their mark in Italian football. Having experienced the training environment first-hand, Donati believes their willingness to work, their physical commitment and their intensity provide an excellent foundation for succeeding in other leagues.
“When I was there, I could see that the main thing for Scottish players, for Scottish football, was going at a thousand miles an hour and playing with intensity.
“As a result, in every training session you see a great willingness from the players to work hard, to run. They really want to give everything on the pitch and they go at a tremendous pace.
“And when you combine that with players who also have football intelligence and genuinely important technical or tactical qualities, it means they can come to Italy, go to England or move to other countries and perform well.
“Because in today's football you need physical strength, you need running, you need athleticism and intensity, and then all the other qualities as well, some players having more than others. But if you lack those physical qualities, it becomes a problem in today's game, because football is incredibly fast.”
Donati has also followed Celtic's more recent fortunes, including the managerial upheaval that followed Wilfried Nancy's arrival from America. He believes the Frenchman was never given sufficient time to establish his approach, pointing to the immediate expectations that accompany managing a club of Celtic's stature.
“They had difficulties last year. A manager arrived from America, and he also lasted only a month. He didn't have time, for the reason I mentioned earlier. He didn't have the time to put his ideas in place.
“At clubs like that, you have to win. You have to win immediately.
“So now they have brought back a manager [Martin O'Neill] who has given a lot to Celtic, and he is also getting good results.”
Donati also reflected on the challenge Celtic face in the Scottish Premiership, where Hearts had made an unusually strong start and threatened to disrupt the traditional contest between the Glasgow rivals.
“This year the championship is competitive because Hearts are involved as well. Normally, it is played between Celtic and Rangers, but this year Hearts have also started extremely strongly.
“It is a competitive championship, and it is nice every now and then for things to be like that.”
Donati's strongest memories, however, are still rooted in his own experience at Celtic. The supporters, the people he encountered and the atmosphere inside Celtic Park left an impression that has endured throughout his career.