Maresca was just 22 when he joined Piacenza from Juventus in 2002, with Agostinelli in charge of the Serie A side.
More than two decades later, Agostinelli believes the qualities that have taken Maresca to the Manchester City dugout were already visible.
“I thought he could become a great coach,” Agostinelli told Football Presse.
“He was a young guy who obviously played regularly with me in Serie A, but he already had the idea of the great midfielder, the great coach.”
Maresca went on to make 31 Serie A appearances for Piacenza during the 2002-03 season, scoring nine goals. Agostinelli, however, did not remain in the job until the end of the campaign, leaving in February 2003.
What stayed with him was the impression made by the young midfielder.
Maresca had come through at Juventus and spent part of his development in England with West Bromwich Albion before returning to Italy, and Agostinelli was giving him an important opportunity to establish himself in Serie A.
“He was a young player who was obviously a starter with me in Serie A,” Agostinelli recalled. “But he had the idea of the great midfielder, the great coach.”
It would be many years before Maresca tested that prediction. His first senior managerial appointment came at Parma in 2021, but the experience was short and difficult.
Agostinelli does not believe that setback should be viewed simply as a failure.
“When he came to Italy at Parma, it wasn't a positive thing, but it served him a lot,” he said.
For Agostinelli, there was a wider lesson in Maresca's experience.
“Besides, in Italy they don't wait for you.”
Maresca subsequently returned to Manchester City, working on Pep Guardiola's staff during the 2022-23 season as City completed the treble. It proved to be an important stage in his development before he took another senior managerial opportunity.
At Leicester City, Maresca immediately demonstrated that he had learned from the difficult start. He took over following relegation from the Premier League and guided Leicester to the Championship title in 2023-24, securing an immediate return to the top flight.
Chelsea then appointed him in 2024.
His first season at Stamford Bridge produced Champions League qualification, the UEFA Conference League and the FIFA Club World Cup. Those achievements eventually led Maresca back to Manchester.
City appointed him as Guardiola's successor on June 29, 2026, giving him a three-year contract and handing him the responsibility of leading the club into the post-Guardiola era. It is his third spell at City, following his work with the Elite Development Squad and Guardiola's first-team staff.
For Agostinelli, however, the most interesting part of Maresca's journey is that the coach was visible before the coaching career had even begun.
“He was already a coach on the pitch,” he said.
That assessment came from someone who had experienced Maresca not as a future manager but as a young player trying to establish himself in one of Europe's major leagues.
Agostinelli's belief has since been tested by every stage of Maresca's coaching career.
Parma showed him how unforgiving management could be.
Manchester City gave him an education under Guardiola.
Leicester demonstrated that he could rebuild a team and deliver promotion.
Chelsea showed that he could handle the pressure of a major Premier League club and win trophies.
Now comes the ultimate examination.
Maresca has inherited a Manchester City side after Guardiola's extraordinary decade in charge, with the club confirming that the Italian had signed until the summer of 2029.
And the man who coached him as a 22-year-old believes the qualities required for the job were already there.
“He was a young guy who was playing, obviously, as a starter with me in Serie A,” Agostinelli said. “But he had precisely the idea of the great midfielder, the great coach.”
Twenty-four years after Maresca first walked into Agostinelli's Piacenza dressing room, the young midfielder has become the man entrusted with Manchester City's future.
Agostinelli saw the possibility long before anyone else could see where it would lead.