READ: Bakkies - Hero or villain?
Botha, 35, announced his retirement from international rugby at the weekend.
He made his Springbok debut on November 9, 2002 against France in Marseille, while his 85th and final appearance for South Africa was against England at Twickenham earlier this month.
"Bakkies played a major role in Springbok rugby. You need a guy in your team of which the opponents are wary of," Du Preez, who was named South Africa's rugby player of the previous century, told Netwerk24.
"We have a few good young locks at the Boks and Bakkies said he doesn't want to stand in their way. I have a lot of respect for his decision and who knows, maybe his body told him it's time to say farewell."
During a stellar career, Botha won the Rugby World Cup with the Springboks in 2007 and was victorious at almost every other level of the game.
He has winners’ medals from the Rugby Championship (Tri-Nations), British & Irish Lions Series, Super Rugby, Currie Cup and Vodacom Cup, as well as the Heineken Cup and French Top 14.
Botha is the seventh most-capped Springbok of all time, is a three-time SA Rugby Player of the Year nominee (2003, 2004 and 2005) and holds the world record for the most Tests as a lock combination in the starting line-up with Victor Matfield (63).