Etzebeth not fit for Singapore trip
Etzebeth has not recovered fully yet from a calf strain he suffered in training five weeks ago.
"Eben [Etzebeth] is unfortunately not available for this one," said Stormers head coach Robbie Fleck.
"There was a bit of a delay in his recovery. It has been advised by the medical staff not to push him, and the best for him and the team is that he takes another week to get ready for the Bulls and the Cheetahs.
"He has missed a fair bit. I prefer him to be back as soon as possible to be honest. We got some big games in this phase three and you want your top players playing on a regular basis."
Meanwhile, youngster Khanyo Ngcukana will travel with the squad to Singapore to provide cover in the backline
The Stormers have a shortage of outside backs at the moment with Leolin Zas' suspension. The Cape side also Dillyn Leyds earlier in the season to a long term injury.
Fleck revealed that scrumhalf Godlen Masimla was due to travel with the squad to cover both scrumhalf and wing, but he got concussed on the weekend in a Currie Cup match against the Sharks.
Stormers touring squad: Schalk Burger, Nizaam Carr, Damian de Allende, Juan de Jongh (co-captain), Pieter-Steph du Toit, Jean-Luc du Plessis, Rynhardt Elstadt, Nic Groom, JC Janse van Rensburg, Huw Jones, Oliver Kebble, Vincent Koch, Cheslin Kolbe, Siyamthanda Kolisi, Johnny Kotze, Frans Malherbe (co-captain), Mbongeni Mbonambi, Khanyo Ngcukana, Sikhumbuzo Notshe, Siyabonga Ntubeni, JD Schickerling, Louis Schreuder, Brandon Thomson, Kobus van Wyk, Alistair Vermaak.