"We knew he had exceptional characteristics, out of the ordinary," Ortega said on Spanish radio, explaining that Leganés monitored Diomandé for two years in Ivory Coast before signing him once he turned 18.
After recovering from an injury, the club arranged a friendly between the first team and academy players specifically to assess him.
"He was the best. He scored a great goal and Borja Jiménez said he wasn't going back to the reserves," Ortega recalled, adding that senior players themselves pushed for his registration to be fast-tracked once they saw his impact in training.
Offers began arriving within months of his La Liga debut, and Leganés tried to extend his contract to raise his release clause from €20 million to €30 million, but ran out of time before he moved to RB Leipzig. Ortega declined to disclose figures for confidentiality reasons but said the structure of that sale left Leganés well placed for a future payday.
"We secured a more beneficial agreement, above all thinking about the club's future," he said — a deal that, according to former team-mate Sergio González, saw Leganés's original €1.5 million outlay grow to a €20 million fee from Leipzig and now around €100 million from Real Madrid.
Beyond his footballing qualities, Ortega pointed to Diomandé's temperament as central to his rise.
"He made his Bernabéu debut at 18 and his legs didn't shake. He has an incredible self-belief," he said, comparing his style — "keeping the distances in mind" — to Lamine Yamal for his ability to unbalance defenders and to Ousmane Dembélé for his two-footed ability. Asked about a potential move to Real Madrid, Ortega was unequivocal: "I'm convinced he has more than enough to succeed there."
The escalating fee — from a modest academy signing to a fee near €100 million in barely three years — reflects how quickly Diomandé's stock has risen since his breakthrough at the Butarque, where he arrived only after Leganés's scouting network flagged him through academies the club's previous ownership operated in the United States and Dubai.
For a club of Leganés's size, retaining a sell-on interest in a player now poised to join one of the world's biggest clubs represents a rare and significant financial windfall.