The 19-year-old Chelsea midfielder was the youngest member of Southgate’s group which travelled to Czech Republic for the tournament, featuring the last eight contenders in Europe
And despite being knocked out after the group stage, Loftus-Cheek impressed during his two appearances from the bench against Sweden and Italy.
"I think we got that about right, the games he came into were games in which we needed to take risks and he’s still learning the game tactically," said head coach Southgate after England's return home.
"He was able to go on and play with freedom and it was a positive experience individually.
"We thought he could have an impact in the way that he did, but I’ve got to be a bit protective of him as well."
Loftus-Cheek came into the group late after previously impressing for England U19s through the season and making his Premier League debut for Chelsea in the later stages of the term.
He made his U21s debut in the win over Belarus prior to the Euro Finals and then played a part in the victory against eventual champions Sweden and the unfortunate reverse to Italy in the tournament.
The Lewisham-born playmaker is likely to feature in Southgate’s squad going forward as plans turn towards the next Euro Championship campaign, which starts in September.
But Southgate is keen not to put too much pressure on the youngster, who Chelsea boss Jose Mourinho has already said will be part of his first-team squad in the new season.
"There’s a danger as a coach of over-praising young players and creating a problem for them going forward," acknowledged Southgate.
"We want to make sure he gets the right level of exposure at the right time because in the end, we all want a good player to come through, so we’ve got to keep challenging him.
"I’m not just talking about Ruben, but collectively, as too much sugar for them is going to be no good.
"You’ve got to make sure they recognise that there’s always another level they can go to."