Sale wing Marland Yarde says some of his team-mates have received death threats relating to how they have marked the Black Lives Matter movement.
The club's South African players have been criticised by their country's sports minister, Nathi Mthethwa, for opting not to take a knee ahead of Gallagher Premiership matches against Harlequins and Exeter.
Sharks players had appeared in anti-racism t-shirts before both games.
Springbok World Cup winners Faf De Klerk and Lood De Jager were among those who did not.
In the aftermath of the Harlequins match, Sale director of rugby Steve Diamond said: "I think it'll be a storm in a tea cup.
"We all wore the rugby against racism T-shirts, which we thought was important, but I don't think it's too much to worry about if I'm honest."
England forward Billy Vunipola said he did not take the knee before Saracens' game with Bristol last week because of his Christian faith.
The PA news agency has contacted Sale for comment.
