The much anticipated return of loose forwards Schalk Burger and Nick Koster for the Stormers' clash against the Lions on Saturday has been put on hold.
Stormers coach Allister Coetzee said on Monday that both players were experiencing pain and had been unable to pursue rehabilitation programmes.
"Before the Super Rugby break we thought they would return against the Lions," said Coetzee.
"Their operations were successful but both suffered bone bruising so we're looking at another two weeks before they are available."
Better news from the Stormers camp is that lock Andries Bekker will run out against the Lions after missing two matches before the break for the international season.
"He's looking good, back in training and the break has done him a world of good," said Coetzee.
"We'll always need to manage players and he'll be monitored closely."
The Stormers' training session on Monday proceeded without Springbok squad players.
"Joe Pietersen is down with flu, Bryan Habana's resting because of a knock to the knee, but needs a break after playing non-stop since the start of the year.
"Eben Etzebeth has a stiff ankle and Gio Aplon as well as Jean de Villiers are rested.
"Steven Kitshoff returned from the Baby Boks and he's played five games in two weeks.
"I know from past experience it hasn't always paid off to pick the returning Boks and its likely that some of them will be rested on Saturday," said Coetzee.
Coetzee still has a fair amount of selection concerns because first-choices lock Rynhardt Elstadt is under suspension and injury-hit Duane Vermeulen will only be available in a month's time.
The flank Pieter Louw who announced his comeback in May after retiring prematurely told Coetzee on Monday that he had decided to return to business instead and won't be available.
Coetzee said it had come as a surprise because the 64-times WP capped Louw had done well to pick up his fitness and conditioning.
Coetzee said the Stormers parted with flank Nick Fenton-Wells, who has requested permission to pursue a contract with Aviva Premiership club Saracens.
Coetzee said lock Quinn Roux was a strong candidate to play on Saturday.
"He's had one match for the Stormers and we were pleased with his performance," said Coetzee.
"He's showed that he's capable and before his injury it was likely that he would have been chosen ahead of Etzebeth."