All 23 Italy players, coach Cesare Prandelli and team staff toured the system that Nazi Germany operated during World War II. They were escorted by three Italian survivors of the Holocaust — 81-year-old Samuel Modiano, 84-year-old Hanna Weiss and Piero Terracina.
At Birkenau, Italian players sat on rail lines once used to bring prisoners in as the survivors explained their experiences of horror and survival after their families were exterminated. Moved to tears, players then embraced the trio one by one.
"The image that stuck in my eyes was when they showed us their tattoos, the numbers on their arms," Italy defender Giorgio Chiellini said. "And the way they told us about being taken away from their families right there on those tracks. I think their stories touched all of our hearts."
As Italy walked out, the Netherlands squad arrived for a similar visit. Wearing dark vests and coats, grim-faced Dutch players moved from room to room in a solemn procession. Some with hands stuck deep in their pockets, others snapping pictures of the austere surroundings as they were led around by a guide, the Dutch visit almost coincided with that of the Italians.
"I just wanted to go because it is a part of your education and I wanted to see it with my own eyes," coach Bert van Marwijk said.
The contrast of the day could not have been sharper since the team held a public training session in the heart of Krakow drawing about 25,000 cheering and celebrating fans.
Even hours later, after the evening training, captain Mark van Bommel was reduced to just a few words.
"You can say a lot of things, but for me it was really impressive," he said.
The morning stunned both Dutch and Italian players.
"It leaves you in shock. You can't not come here," Italy midfielder Riccardo Montolivo said. "It's a time for introspection."
Italy goalkeeper Gianluigi Buffon deposited a bouquet of white, red and green flowers — the colours of Italy's flag — at an execution wall and each player deposited a candle.
"Our generations are fortunate in that we've only seen these horrors in films and books," Chiellini said. "But having it right in front of your eyes, where it happened, and hearing from those who lived through it, is really incredible.
"I told my brother, 'If you come to see a match, you should go to the camps, too. It leaves you with emotions that are difficult to forget,'" Chiellini added.
As the survivors spoke, other visitors to the camp snapped photos of Mario Balotelli and Italy's other well-known players.
"I hope this visit serves a purpose for them, and that they'll return home with a bit more baggage, and that they'll understand there's no difference between one person and another," Modiano said. "We're all equal. There are no different races."
Modiano was 13 when he was deported from the island of Rhodes, which was part of Italy from 1912-47. It is now part of Greece.
"Rhodes was all Italian. We were taken by the Germans in Rhodes as Italian Jews and deported to the concentration camps," he said. "The trip from Rhodes lasted a month."
The entire Jewish community of 2,500 was deported by the Germans, according to Modiano.
"In 6-7 months at Birkenau, only 31 men and 120 women survived," he said. "So if the Russians had arrived a week later, nobody would have survived. After many centuries on that beautiful island, the community was completely erased."
Auschwitz-Birkenau is the most notorious of a system of death camps that Nazi Germany operated on Polish soil after invading the neighbouring country during World War II. The Holocaust was carried out to a large extent in occupied Poland, because it had Europe's largest Jewish population and it was at the heart of a railway network that allowed the Nazis to easily transport Jews there from elsewhere in Europe.
Historians estimate that between 1.1 and 1.5 million people died in Auschwitz, either in gas chambers, from being shot or from starvation and disease. Most of the victims were Jews, but the Nazis also killed many Poles, Soviet prisoners of wars, Gypsies, Jehovah's Witnesses, gays and political opponents there.
"Maybe they've seen the documentaries, but it's completely different when you actually come to the place and see it with your own eyes and hear some witness accounts, because there are not many of us alive today," added Modiano, who now lives in Rome.
"For years, we've been asking ourselves why we survived and others didn't. Maybe God chose some of us to tell our stories so this never happens again," Modiano said. "That's our mission."
Today, Auschwitz is one of Europe's most visited Holocaust remembrance sites, with a record number of 1.4 million visitors last year. While the large number of visitors is seen as important for Holocaust education, the mass tourism is also adding strain to the barracks and other structures. Many are already in a state of severe dilapidation because of the passage of time, and the officials overseeing the site are struggling to preserve what they can.
Weiss was 16 when she arrived at Auschwitz from Fiume, a town that was part of Italy from 1924-47 and is now in Croatia. She moved to Israel and became a nurse after losing her mother, sister, grandparents and other relatives during the war.
She spent 8 1/2 months at Auschwitz, from May 1944 until the camp's liberation by Soviet troops in January 1945.
"When I arrived in Israel after the war, nobody wanted to listen to us," Weiss said. "Now people are listening, so that's welcome."
Weiss wasn't sure what to say about problems of anti-Semitism inside some football stadiums.
"I don't know the national team and I don't know the players, but I hope that this visit can help," Weiss said. "The thing that disturbs me most in Italy and in Europe is denial of what happened."
Added Chiellini, "We've already been affected by these things at the stadium, and now we're even more sensitive to these issues."
Associated Press writers Raf Casert in Krakow, and Vanessa Gera in Warsaw, contributed to this report.