The out-of-contract World Cup winner was on the verge of joining Galatasaray but he had a change of heart and instead opted to pen a two-year deal with the Swiss Super League side
The former Italy international, who had been expected to join Turkish outfit Galatasary, has put pen to paper on a two-year contract with the Swiss Super League side.
"Money had nothing to do with this choice," Gattuso explained. "I decided to come to Sion because I was convinced by the club's project.
"Many people advised me not to accept, but I wanted to take on this challenge after speaking with the president [Christian Constantin]. I am here to win; we want to challenge Basel [for the title]."
The aforementioned Constantin, meanwhile, revealed that Gattuso has already demonstrated his famed committment to the cause.
"He was on holiday with his family in Spain but he left everything to come her and start working with his team-mates.
"He is one of those who puts his heart, head and legs on the line on the field. He is the biggest player in the history of the club."
Gattuso had initially hoped to rejoin Rangers but the Scottish club were not in a position to bring the World Cup winner back to Ibrox because of their current financial problems.
The 34-year-old was beset by career-threatening ocular problems last season but he made his return in time to play a role in the title run-in.
However, Gattuso featured only sporadically in the first team and explained after being left on the bench for the duration of the Rossoneri's 4-2 derby defeat by Inter last month that he knew his time at San Siro was up.
Gattuso arrived at San Siro from Salernitana in 1999 and won two Scudetti and two Champions Leagues during his time with the Diavolo.