That pair are regarded as two of the greatest midfielders of their generation - if not all time - and while Xavi and Iniesta were dazzling at the Camp Nou, Olmo was watching on from Barcelona's youth ranks.
It meant that Olmo had one of the best seats in the house to see them pull the strings as Pep Guardiola's Barcelona romped to an historic sextuple in 2009 - a feat only replicated by Bayern Munich in 2019/20.
A Catalan himself, Olmo had moved to La Masia from city rivals Espanyol as a nine-year-old in 2007. It's little wonder, then, that he lists Iniesta and Lionel Messi as his "sporting role models", but his decision to jump ship to Croatian outfit Dinamo Zagreb at 16 certainly dropped jaws.
Olmo was expected to follow in the footsteps of his illustrious predecessors and move up the ranks from Barca's B team before graduating to the first XI. But he had other plans.
"I didn't care where it was or that it was outside the big five leagues," wrote Olmo in The Players' Tribune. "I knew nothing about Croatia, but I knew at Barca I was in danger of being lost in the system, becoming just another player, with no clear pathway to the first team."
His father Miquel went further, explaining to The Guardian: "They told me I was crazy. They massacred me for it, saying I was ruining my son's career."
Olmo says "how did I go from Barcelona to Zagreb and then on to Leipzig?", is "the question I get all the time". Now, though, few people will be doubting his decision to have sought pastures new outside of his homeland, or to be as accusatory of his dad.
After all, Olmo is heading to a European Championship with Spain on the back of a fine 2020/21 campaign with Leipzig that saw the 23-year-old score five league goals and create a team-high nine assists in 32 appearances.
In doing so, the attacking midfielder has established himself as a key figure for both club and country. He has also found the back of the net with critical goals in each of his two most recent internationals, earning Spain narrow wins over Georgia and Kosovo in 2022 FIFA World Cup qualifying.
Xavi and Iniesta were central to Spain's footballing dominance from 2008 to 2012, which brought the country European glory in 2008 and 2012 as well as the World Cup trophy in 2010.
Olmo was still at Barcelona throughout that period and the efforts of the national team continue to inspire the playmaker.
"If you look at the teams between 2008 and 2012, they were incredible," he said after marking his senior international debut with a goal against Malta in 2019. "Xavi Hernandez, Andres Iniesta, David Silva, Sergi Busquets and Santi Cazorla, they were all so impressive."
Now it's Olmo catching the eye with his unmistakable talent. It's led to Spain coach Luis Enrique - a former Barca man himself - once reportedly telling the Leipzig player: "You can tell you've been at Barcelona."
It's easy to see what Enrique means. Olmo loves being in possession, is comfortable when he gets the ball and brave in his decisions, just as Xavi and Iniesta where throughout their storied careers.
Outgoing Leipzig coach Julian Nagelsmann, whose personal call to Olmo was decisive in the Spaniard electing to join Die Roten Bullen when a host of Europe's top clubs came calling in 2020, has been equally impressed after 18 months together.
"He has exceptional abilities and is very safe with the ball. When he gets put under pressure, he knows how to provoke a foul," Nagelsmann revealed.
"He adapts better and better. He's a great talent and a top guy who wants to learn, who has the necessary modesty but also the ambition and the self-confidence and also opens his mouth sometimes and says that he wants to play.
"He wants to be given the chance. I like that."
Like Xavi (1999 FIFA World Youth Championship) and Iniesta (2001 U16 and 2002 U19 UEFA European Championships), Olmo has also picked up a youth tournament winners' medal for his country (2019 U21 UEFA European Championship).
In that tournament, Olmo scored in both the semi-final and the final as Spain beat Germany to the trophy courtesy of his winner in the showpiece. His three goals were more than any of his teammates, and Olmo will now be hoping to have a similar impact this summer. He'll aim to usher in a period of club and national team dominance as the creative force of two highly ambitious setups, just as Xavi and Iniesta managed to great acclaim before him.