During World War II, he was enlisted in the Youth Work Camps, and upon his return, he joined the U.S. Fumel Club, where he played alongside Pierre Taillantou and Gaston Combes.

Over four seasons, he became one of the most notable players in the French Championship, primarily as a fullback for his club, only challenged in the national team by Puig-Aubert.

At the age of 26, Barreteau retired from professional rugby and joined Lavardac XIII as a player-coach, achieving success with three second-division titles in 1951, 1953, and 1955.

At the age of twenty, he was obliged to join the Youth Work Camps during World War II and spent some time in Germany.

[6] He gradually established himself and became a regular fullback[8] with success, relying on standout teammates such as Pierre Taillantou[7] and Gaston Combes, which enabled U.S. Fumel to compete at the top levels of the French Rugby Union Championship.

[10] In the same year, they also reached the quarter-finals of the Coupe de France, where they were defeated by Aviron Bayonnais, led by Jean Dauger, André Alvarez, and Maurice Celhay, with a score of 8-7.

[8] However, the season started with a setback for U.S. Fumel as one of their key players, scrum-half Gaston Combes, departed for rugby league and joined R.C.

[14] Barreteau's performances drew the attention of rugby league officials, who convinced him to switch codes in December 1945, despite offers from S.U.

Roanne reached the semi-finals of both the French Championship and the Coupe de France but was defeated at that stage by AS Carcassonne (15-3) and XIII Catalan (8-7) respectively.

He was considered for selection to the French national team,[21] and in January 1948, he made his international debut against New Zealand, contributing significantly to France's victory.

President Claudius Devernois, who had been financially supporting the club for fifteen years, noticed a budget deficit that he had been compensating for each season.

In consultation with the French Federation, Devernois was advised to focus efforts on the Lyon region and take over U.S. Lyon-Villeurbanne, located in a more lucrative area.

[30] This transfer was finalized in September 1949, with several players, including Joseph Crespo, Jean Audoubert, René Duffort, Pierre Taillantou, and Henri Riu, along with their coach Robert Samatan, moving to Lyon-Villeurbanne.

[32] Barreteau's stint at Toulouse was short-lived due to organizational challenges within the club, which had experienced three different presidents in the past two seasons and withdrew from competitions in March 1950.

[33][34] After his time in Toulouse, Barreteau took charge of U.S. Lavardac, where he found promising players like Marius Guiral's son and the brothers Gérard and Gilbert Dautant.

[6][35] Serving as player-coach,[36] Barreteau led the team to success in the French Rugby League Championship's second division, winning titles in 1951 against Orange,[35] in 1953 against La Réole XIII, and in 1955 against Facture.