Utility forward Don Armand will join up with the Stormers on Monday as replacement for the injured Michael Rhodes.
Rhodes scored the Stormers opening try in their 18-16 win over the Hurricanes on Friday but has been ruled out of the rest of the tour suffering an ankle injury in the first half.
"It's very unfortunate for Mike who suffered an ankle injury last night," Stormers coach Allister Coetzee said on the Stormers site.
"He's been playing very good rugby since his debut against the Cheetahs and he made a big impact against the Sharks (where he was Man of the Match) and also in the first half against the Hurricanes.
"Like I've said all season long, injuries are not good for continuity, but it's the nature of the beast (in rugby). Our mantra has always been not to concentrate on the injured players, but rather to worry about those players that are available to us."
Armand was meant to be playing for Western Province in the VC (in Bloemfontein) on Saturday, but, instead, he flew back to Cape Town and will now prepare to join his teammates in Auckland.
Speaking about Armand's call-up, Coetzee added,"We're very fortunate to be able to call up someone like Don, who has been part of our squad all year long (until an injury saw him drop out).
"Don was also called up to our squad in Australasia last year. Since then he has gone on to become a regular in the Stormers and WP set-ups and he was also a strong performer for us in the business-end of the 2012 Currie Cup.
"Also, Don, like Mike, can play in the second row or the back row - so it's a like-for-like replacement and will add to our resources on tour. We're looking forward to his arrival and turning our attention to our next assignment - against the Blues."
Armand, 24, has played nine matches for the Stormers (his last outing coming against the Crusaders on March 30 - when he picked up an intercostal rib muscle injury), as well as making 19 appearances for Western Province.
Meanwhile, Coetzee also confirmed that flanker Siya Kolisi - a late withdrawal against the 'Canes with a groin injury - would hopefully be able to rejoin team training from Tuesday of next week.
The Stormers coach concluded: "Losing Siya before the game was a blow, but we're hopeful that he can be eased back into training next week in order to prove his fitness for the Blues match (next Friday)."