With 81 caps to his name, the 36-year-old former New Zealand international is the third most capped player in All Blacks history, and the most capped scrum-half, featuring in both the 1999 and 2003 World Cups.
Now he could be making his final bow in Saracens’ Guinness Premiership play-off clash at Northampton on Sunday.
“I have given a lot to the game over the past 17 seasons, but rugby has given me much, much more,” Marshall said. “My career has made massive demands on them [my family], and now we are all looking forward to going home to New Zealand and settling into something like a normal family life.”
Meanwhile, Sarries’ new wing star David Strettle is one of nine players leaving Harlequins this summer.
Strettle moves across the capital at the end of the Premiership campaign, joining long-serving hooker Tani Fuga out of the Quins’ exit door after he signed for Bristol.
Aston Croall, Waisea Luveniyali, Tosh Mason, Neil McMillan, Nils Mordt, Steve So’oialo and Gonzalo Tiesi have also been released.