30-year-old Osbourne was carried off on a stretcher in the goalless draw with Shrewsbury after being knocked unconscious when struck in the face by a drop ball struck by Anthony Grant.
Despite Osbourne’s injuries not being considered too serious, the Football Association's concussion protocol advises players not to return to action for at least seven days after the injury.
Head Physio Marc Czuczman, speaking via the club's official website - Saddlers.co.uk - explained; "He was knocked out for about 45 seconds to a minute. We had to deal with it as a concussive injury, which is why we gave him oxygen and stretchered him off.
"Ten, 15 minutes after the game he was fine and having a laugh with everyone, but he couldn’t recall the event at all. We have to go through the FA guidelines for concussion management.
"The quickest you can turn it around is seven days, but that is reliant on the player having no symptoms after the event or the next day. However, the next day he had a headache, which is one of the symptoms.
"He has to be completely free of symptoms for 24 hours before we can start stage one of the progressive return to sport protocol. Because he had symptoms on Wednesday and it only just cleared yesterday, he’ll be ruled out for the next two games.
"Once he’s been 24 hours free, we can start through the progressive FA guidelines. Today he’ll do 15 minutes on a bike to see how he responds. That progressively increases until he’s back to full sport.
"He’s basically on a rest period now but we’d like to think he’ll be back in full training on the Monday before the Luton game."