M. Valletta is registered as a Luxembourg-nationality forward in AC Milan's player database for the 2025-26 season, with limited senior minutes recorded against the squad. Verified independent biographical and career information about him is currently very limited at the time of writing, and he does not yet have a meaningful public match record at top-level European football.
Public information about him will be updated as more career and biographical detail becomes available — including birth date, prior clubs and international background — once it can be reliably confirmed from independent sources.