Emmanuel Adebayor scored in extra-time to send Tottenham through on away goals, but his evening was overshadowed by the racist behaviour of a pocket of Inter fans.
Some Nerazzurri supporters monkey chanted when the Togo striker was the focus of play in the San Siro ground while one fan had brought an inflatable banana to the game.
Inter were fined £43,000 for waving inflatable bananas and unfurling abusive banners aimed at Mario Balotelli and his team-mate Sulley Muntari in last month's Milan derby, while the club also received a £12,900 fine after sections of their support sang racist chants about the former Manchester City striker during a game against Chievo.
Friedel, a professional of 18 years who has played across Europe and the United States, is aware of UEFA and FIFA's campaigns to try to eradicate racism in the game, but the 41-year-old thinks the problem will be hard to stamp out because it runs so deep in society.
"They (UEFA) can do what they are doing and set up campaigns and things of this nature, but until certain countries want to set up their infrastructure and school systems, and they go inside the parents' heads and the households, things will not change," the Spurs goalkeeper said.
"When they do that then things will change, not so much (through) campaigns and things of that nature.
"I think education should be more stringent."