The Free State team has already signed Clayton Blommetjies, Bees Roux, Willie du Plessis and Sergeal Petersen in a bid to strengthen their Super Rugby squad for next season.
They have lost a number of key players, and may lose Adriaan Strauss and Trevor Nyakane, and will hope that the new players will bolster the team.
Du Plessis has experience in Super Rugby, having played for the Melbourne Rebels and Stormers.
Du Plessis attended Paul Roos Gymnasium in Stellenbosch before starting his rugby career with Australian rugby league side Sydney Roosters.
Du Plessis joined the Melbourne Rebels in 2010. He returned to South Africa two years later, joining the Stormers. He left for France after one season with the Western Province side.
The Cheetahs play the Lions this week in their last Super Rugby game of the season.
