During the 1970–71 season, Gress returned to his homeland and joined Olympique de Marseille, then two-time French champions.

From 1973 to 1975, he came back to RC Strasbourg, before moving for one year to Neuchâtel Xamax in Switzerland and ending his playing career in 1977.

Gress completed 290 matches (201 for Strasbourg, 89 for Marseille) in France and scored 28 goals; in the federal league he came on 149 times.

Since 1977, Gress has worked as a football manager, receiving his first job in his home town at RC Strasbourg, where he had won the 1979 French championship, and where he returned again in 1991 for three years.

In addition, he worked in Belgium, Austria and in Switzerland, where in 16 years (including twelve with Neuchâtel Xamax) he won two national championships and the cup.