Medical experts have issued a troubling warning to Detroit Lions star Jack Campbell following his recent neck injury, warning that he may never step foot on an NFL field again.

Linebacker Campbell, 26, suffered the terrifying injury against the Minnesota Vikings on Sunday after he lowered his head to make a tackle in the fourth quarter. 

The defensive star laid on the turf motionless and needed to be carted off the field before being transported to the hospital, where he has since remained. 

In the days that followed, the franchise have given tentative and vague updates on Campbell's condition, revealing only that his condition is 'improving' amid treatment.

Then, on Wednesday, Campbell broke his silence with a lengthy statement, thanking fans for their support while revealing he has 'full movement' in his lower body.

He said: 'I'm incredibly encouraged by the progress I've made in such a short period of time. I have full movement in my lower body, and I'm continuing to make progress with movement in my upper body.

'I know there's still work ahead, but I remain very optimistic. I'm taking things one day at a time, staying positive, and focusing on getting better.'

However, while the Lions stars remain optimistic about his recovery, medical experts have poured cold water on the suggestion that he could soon make a return. 

Dr Mohammed Faraz Khan, a neurosurgeon at Hackensack University Medical Center, revealed that Campbell's statement actually raised more concern among his team.

Asked whether he was worried about the Lions star's update regarding his movement struggles, Dr Khan told the Daily Mail: 'From a neurological standpoint, yes.

'When someone has not fully recovered movement several days after a neck injury, that raises our level of concern. That said, his statement describes continued improvement, which is encouraging.'

Dr Khan, who also serves as the Assistant Professor of Neurosurgery at Hackensack Meridian School of Medicine, continued by delving into the potential injury itself. 

'This is not a routine consequence of a football collision. The reported difference between his upper and lower body function raises concern for an injury involving the spinal cord in the neck. 

'One possibility is central cord syndrome, where the arms and hands are affected more than the legs. That pattern could fit what has been described.'

Central cord syndrome, as explained by Dr Ari Berg, a spine surgeon at Hackensack University Medical Center, is 'a specific type of incomplete spinal cord injury'.

He told the Daily Mail: 'To understand this, it helps to picture the spinal cord's anatomy. The nerve fibers that control arm function run through the very center of the spinal cord, while the nerve fibers controlling the legs are located on the outer edges. 

'When a player suffers a hyperextension injury, it can compress and bruise that central part of the spinal cord, leaving the outer 'leg' fibers relatively spared.

'This syndrome, or a similar temporary trauma known as 'spinal shock,' are the most likely explanations for his symptoms. It is a serious condition that can be quite painful, often causing the arms to become highly sensitive while diminishing grip strength.'

So, what does this all mean? Well, according to Dr Khan, it unfortunately casts major doubt over Campbell's NFL future. Even if the Lions star does get physically fit again, there are a range of aspects that would need to be considered before an NFL return.

When asked whether Campbell's career could be done, Khan said: 'Yes, that is a real possibility with a cervical injury causing neurological deficits. 

'Before considering a return, his doctors would need to assess his strength, neurological function, spinal stability and imaging. They would also have to consider whether another collision could put him at unacceptable risk. 

'A good recovery does not automatically mean a safe return to football. 

Despite these harsh realities, Dr Berg pointed out that there is reason for hope. 'The fact that Campbell has already regained movement in his lower body and is seeing progressive improvement with his upper body is actually a very encouraging sign.

'When you're dealing with significant neck trauma, swelling and inflammation around the spinal cord are common, and these can take time to resolve. Being a young, highly conditioned athlete is in his favor.'

In his emotional statement, Campbell acknowledged that there will be 'challenges ahead' but remained optimistic, adding that 'with my faith, my family, and so many people in my corner, I know we'll get through this.'

But, what are those challenges? Dr Khan explained: 'The first priority is preventing additional injury to the spinal cord. 

'That includes protecting the spine, maintaining adequate blood pressure and oxygen delivery, and closely monitoring his neurological examination.

'If imaging shows significant ongoing compression or instability, surgery may be necessary. If the injury is primarily bruising of the cord without a surgically treatable problem, management focuses on supporting recovery and preventing complications.

'Physical and occupational therapy begin when medically appropriate, working on strength, joint movement, coordination, and especially hand function. 

'Recovery can continue over weeks and months. It takes patience, and repeated examinations will tell us much more than any single public update.'

Meanwhile, Dr Berg added: 'A major component of his rehab will likely involve fine motor skills and regaining grip strength. 

'This is a highly individualized process, and the medical staff likely will carefully pace his therapy to match his body's healing rate without putting any undue stress on his spine.'