Roos’ omission from the Springbok squad has been a talking point given his superb displays in the United Rugby Championship.
It has led to suggestions of a rift between the player and Erasmus, but the latter took to X on Thursday to deny this was the case.
“He’s a world-class player and will play many Test matches for the Boks, we just have two really good eights in Jasper (Wiese) and Kwagga (Smith) and in my opinion they are still delivering at a higher level than Evan! So who to drop?" Erasmus said.
“One thing is a given, he is a Test match player and will probably make it in 2027.”
The Springboks have also used captain Siya Kolisi in the number eight position this season.
Roos, 25, is on a stand-by list of players who will be called up in the case of injury for the teams Autumn International series. He has won eight caps since making his Springbok debut in 2022.
South Africa on Japan at Wembley Stadium in London on November 1 before travelling to Paris to meet France a week later in a repeat of their 2023 Rugby World Cup quarter-final.
They tackle Italy in Turin on November 15 before the latest instalment of their burgeoning grudge match with Ireland in Dublin on November 22.
They finish the tour against Wales in Cardiff a week later.