The Scotland captain was among millions of football fans who watched in shock as medical staff gave the 29-year-old chest compressions on the pitch as they tried to resuscitate him while his distraught team-mates formed a protective circle.
Eriksen is now recovering in hospital after Denmark team doctor Morten Boesen confirmed the midfielder had suffered a cardiac arrest, and Robertson admitted he was almost drawn to tears by the incident and the reaction of the Danish players.
"I'd like to send my well-wishes to Christian Eriksen, his family, all the Danish players, the Danes as a country," the Liverpool full-back said. "What we witnessed was scary for the football community. Luckily the news today is a wee bit more positive.
"The way the Danish players dealt with what must have been a heart-breaking thing for all of them, they stood up to it. That will be the picture I remember and everyone should remember because, when one of their friends was in a bad place, they stood up and protected him.
"Whatever else happens in this tournament, for me they will be the heroes.
"Their captain (Simon Kjaer), it nearly brought a tear to my eye the way he stood up."