In 2007-2008 Diego joined the youth team of Monte dei Paschi Siena, taking part to the U15 national finals averaging 30,17 points per game, and eventually being rewarded with the MVP award of the tournament, receiving the award from Carlo Recalcati, head coach of the senior Italian men national team.

On September 25, 2009, Diego made his first appearance with the Monte dei Paschi senior team, led by coach Simone Pianigiani, in an exhibition game vs the Efes Pilsen Istanbul.

Despite the 3-year contract, and the skills showed at this level too (despite the few minutes played), at the end of the season Diego decided to part with Sassari.

[2] During the two season at Pesaro Diego has played 18,2[3] and 18,3[4] minutes per game providing his leadership and playmaking skills to the team and helping the VL to remain in the Italian first league.

In 2009-2010 took part in the U18 European Championship held in Vilnius, Lithuania (selected to play with a team made of athletes older than him) In 2010-2011 was a member of the U18 Italian National team, taking part to the U18 European Championship held in Wroclaw, Poland, where Italy finished 4th.

In 2011-2012 took part with the U18 3X3 national team in the first 3X3 world championship, held in Rimini, Italy, finished 3rd winning the bronze medal.