Born in 2002 in Mar del Plata, Argentina, he began playing football in his homeland at the age of six for Kimberley before joining the Velez youth sector. His debut as a pro, however, took place in Italy in the shirt of the Juventus Under 23 (from season 2022/23 Juventus Next Gen) in the Serie C Italian Cup match against Pro Sesto. At the end of the 2021/22 season, he totaled 34 appearances in all competitions, enriched by five goals. Prior to turning professional, Soulé played 36 matches with the Juventus Under 19 team, which expanded his wealth of experience and readied him for his Serie C debut.

In the 2021/22 season Matías also made his debut for the First Team, away at Salernitana on November 30, 2021. Then another appearance against Venezia. In the 2022/23 season, his first game came on the opening day of Serie A, on August 15 in the 3-0 victory over Sassuolo at the Allianz Stadium.