Giovanni Haag

Haag made his professional debut with Nancy in a 1–0 Ligue 2 win over Red Star on 23 November 2018. On 10 July 2023, Haag signed a two-year contract with Rodez. On 30 August 2024, Haag moved to Fortuna Düsseldorf in Germany, scoring twice as the club finished sixth in the 2. Bundesliga. On 1 September 2025, Haag returned to France and joined Red Star in Ligue 2, featuring in 27 of a possible 31 league matches and helping the Parisian club finish fourth, just four points shy of automatic promotion to Ligue 1. Of his 116 Ligue 2 appearances, 53 came for boyhood club Nancy, where he made his professional debut in 2018. He also went on to represent Rodez AF and Red Star FC in the same division.

Lion City Sailors

Haag was announced on 4 August 2026 as the latest addition for Singapore Premier League champions Lion City Sailors, signing on a 2-year deal.

Haag is of Italian descent through his mother, who died when he was 15 years old.