"he's really upbeat," Cameron said. "You could imagine, that's what makes those guys who they are and what they are. They're competitors, and they think a little differently than the rest of us sometimes. They can't imagine not playing, and they want to be back out playing as quickly as possible.
"Now with all that being said, we have to let this thing play out, and we'll keep you updated."
Green has been visiting this week with the same doctors who worked with him after he sustained his concussion last season in the opener against Cincinnati. He was scheduled for more tests with a neurosurgeon later Wednesday.
Cameron said Green told him the morning tests were "very encouraging."
The Dolphins signed defensive tackle Sam Rayburn to help out because of injuries at the position.
In addition to Vonnie Holliday nursing a slight fracture in his lower leg, Rodrique Wright also has a minor ankle injury.
Rayburn is a former member of the Philadelphia Eagles, with whom he played for four seasons. His best season came in 2004 when he had 46 tackles and six sacks.
Six players missed practice on Wednesday, and Jason Taylor was limited with a neck injury.
Linebacker Channing Crowder, who missed Sunday's game at Houston, was back at practice.