It's fair to say there's not much that would have fazed the Milan team of the mid-2000s.
That side contained the likes Paolo Maldini, Andrea Pirlo, Cafu and Kaka and under Carlo Ancelotti won the Champions League twice and reached another final.
But a member of the side that lifted the trophy in 2007 has recalled the almighty fright Gordon Strachan 's Celtic side gave the Italian giants at the last 16 stage.
Massimo Oddo recalled on an Instagram live chat: "It was an under-par Milan, domestically they were having a hard time and when I arrived they were not in the top positions in the league.
"In the draw we were happy to get Celtic, on paper they were the most beatable team.
"We went to play the first leg in a wonderful stadium with fans who create an incredible scene.
"We didn't play well, we drew 0-0 and risked losing it.
"We were convinced we'd go through in the return leg, but the game proved to be difficult.
"Celtic caused us problems and they took us to extra-time. Then Kaka invented this goal out of nothing, and that was the birth of the great Kaka who took us to the final."
Milan would go on to win 2-0 against Liverpool in the final, with Filippo Inzaghi striking twice.
In the knockout rounds they put four past Bayern Munich over two legs and scored five against Manchester United, but against Celtic they could only manage one goal in 210 minutes of play.
