Ricci was named adviser to hockey operations Tuesday while Marchment was assigned to scouting and player development.
"Mike Ricci and Bryan Marchment are two of the fiercest competitors to play in the National Hockey League," Sharks GM Doug Wilson said in a statement. "We have always said that we will look at all ways to improve our organization on and off-the-ice and having these two leaders work with our current and future players is a fantastic opportunity for our club."
Ricci announced his retirement Aug. 13, ending his 16-year NHL career. The 35-year-old played for the Sharks from 1997-2004.
Marchment, who last played in the NHL with Calgary in 2006, spent parts of six seasons in San Jose from 1997-2003.