Leyds out for the season
Scrumhalf Jano Vermaak is another player who will be out for a lengthy period on the sidelines after he had a 
"serious operation" on his neck and will be out for up to three to four months.
Stormers coach Robbie Fleck confirmed the injuries via teleconference from Buenos Aires on Sunday after his team edged the Jaguares 13-8 in a Super Rugby fifth round tie.
Leyds suffered the knee injury in training on Tuesday, while Vermaak has been out of action since the 13-18 defeat to the Sharks two weeks ago.
The duo will be a big loss to the Stormers, but Fleck also had some good news regarding the return of Springbok centre Damian de Allende and flank Rynhardt Elstadt.
De Allende, who suffered an ankle injury while playing for Japan Top League side the Kintetsu Liners in December, is currently training with the Western Province Currie Cup squad and is expected to be fit for the Stormers next match against the Sunwolves on April 8.
Elstadt is also expected to be fit for the Sunwolves clash after recovering from his groin injury.
Meanwhile, Fleck believes his team showed a lot of determination to beat a Puma-laden Jaguares outfit on Saturday.
It was the Stormers first-ever Super Rugby match in Argentina.
"The guys showed a lot of guts," said Fleck. "
"The fact that we could win ugly away from home in a hostile environment is a very good thing for our team.
"It was ugly in the second half, but from our point of view, we had a very good first half. The plans that we put in place were pretty clinical."
Fleck also had a lot of praise for co-captain Frans Malherbe, who was ill leading up to the game.
The prop was a force in the scrums and he also played out of his skin in open play – especially in defence.
"He was in bed the whole of Friday with food poisoning. He did not come to one meeting and did not train on Friday.
"It's a massive credit to him. The try-saving tackle he made right in the beginning of the second half showed his character and that is why he is one of the co-leaders. He is fantastic rugby player and just really personified what we are about," Fleck added.
By Warren Fortune
@FortuneWarren
@rugby365com
