During his ownership of FC Sion, Constantin has employed over forty head coaches and incurred a transfer ban from FIFA due to the signing of Essam El-Hadary. This transfer ban then led to the club being expelled from the 2011–12 UEFA Europa League as players signed during the transfer embargo were used in competition. Yet under his presidency, the club also experienced considerable success, such as its Swiss Cup victories in 2006, 2009, 2011 and 2015.
