The Bulls will be without captain Pierre Spies for the remainder of the 2014 Super Rugby season after he was ruled out due to an arm injury on Monday.

Spies again suffered a bicep muscle injury to his upper arm, the same injury that sidelined him in June last year, resulting in the No. 8 missing the remainder of the 2013 season.

According to Bulls team doctor Org Strauss, Spies complained about pain in his bicep after the Stormers warm-up match.

An MRI scan and ultrasound of the area was done and did not show any damage, but as the pain did not go away after the opening Super Rugby match against the Sharks, two other opinions were also called for.

Specialists found bleeding and a rupture of the bicep after more scans and decided to take immediate action.

Spies will be operated on this week at Unitas Hospital and will miss at least six months of rugby, effectively ending his 2014 Super Rugby campaign.

Bulls coach Frans Ludeke admitted the loss of Spies is a significant setback.

“Especially as we recently just lost Arno (Botha) for the rest of the season," he said.

"Both players are Springboks, were an important part of our game plan and contributed tremendously in the leadership category.

"But we have learned by now that you have to adapt when the injury bogey strikes, so we will have to adjust accordingly."

In other injury news, Strauss confirmed that Deon Stegmann will be seeing a specialist on Wednesday regarding his groin injury.

Dean Greyling sprained an ankle against the Cheetahs on Friday night, but will train on Wednesday.

Mornè Mellett has been declared fit, following his back strain.