The 33-year-old, who famously left Liverpool for Saudi Arabia's Al Ettifaq in a £12m deal during the summer, was met with a chorus of boos from sections of the home support at Wembley when his name was announced before the game on Friday, while his substitution in the second half only drew louder jeers from the crowd.
Though Henderson had already featured for the Three Lions since his controversial move, the victory over Australia marked his first home appearance as an Al Ettifaq player.
While many high-profile players and coaches have been lured to Saudi Arabia on big-money deals this year, Henderson has been singled out for criticism.
During his time at Anfield, Henderson had been a prominent supporter of LGBTQ+ rights from within men's football and his transfer to a country where homosexuality remains illegal was seen by many as the midfielder selling out on his beliefs.
However, Elliott, who watched the England senior side's 1-0 win over Australia while on Under-21 duty, backed his former teammate – calling on fans to 'get behind' Henderson.
“It’s upsetting, Hendo is a massive inspiration, not just to myself but to many around the world,” the 20-year-old said. “For what he has done for England and English football it’s not nice to see.
“It’s his decision, it’s his career. As a nation we need to get behind these players and support them. It wasn’t nice, but knowing Hendo I’m sure it hasn’t fazed him.
“He’s a positive-minded player and person. He just wants to do the best for himself in his career. Everyone is behind him.”
Elliott, who scored twice in the Young Lions’ 9-1 win over Serbia on Thursday, also revealed he is still in regular contact with his old Liverpool captain.
"He has been through a lot in his career and it’s just another barrier he is going to run through, I’m sure," Elliott added.
“We always keep in touch, when we’re here (St George’s Park) and see those guys we are always having conversations and it’s nice to have that togetherness with the seniors.
“Some of the lads, playing for the big teams here, brings everyone together. It’s nice to be around them and it gives us all a target and goal.”
Henderson, meanwhile, initially claimed not to understand the reason why he was booed by supporters, while insisting he is 'not a politician'.