In the summer transfer window, they brought in Italian World Cup winner Gennaro Gattuso, as well as Kyle Lafferty (former of Rangers).
In addition, they bought an until then unknown Brazilian footballer called Léo Itaperuna from the 5th division Club of Arapongas and another forward Mathieu Manset from Reading.
Already signed six months earlier, Oussama Darragi coming from Esperance de Tunis joined the team along with André Marques from Sporting Lisabon.
On 4 September 2012, Manset, Joaquim Adão and Darragi were all disciplined after being found in the early hours of the morning in a Lausanne nightclub the day before Sion's game away to FC Zürich.
Manset's contract with the club was canceled, Adão was demoted to the youth team for one month and Darragi was handed a large fine.
The reasons for that were the transfer of the center back Adaílton to Henan Jianye and the simultaneous injuries of Aislan, Vanczák and Sauthier.
Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.