Former Barcelona assistant coach Juan Carlos Unzue has said that some players are not capable of handling the strain of playing with the club's talisman Lionel Messi.

Unzue, who was assistant to Luis Enrique between 2014 and 2017 at the Camp Nou, said the standards demanded by the Argentine are too much for some teammates.

What has kept Messi [where he is] is ambition and how to live with moments of stress," he told YouTube channel Idolos.

"He self-demands to himself to keep being the best and, as a result, also wants the best around him, teammates, physio, or coach. That produces a great stress that some teammates are not capable of bearing."

Messi almost left Barca in the last transfer window amid speculation of a move to Manchester City and many expect him to leave the club when his contract expires in June.

The 53-year-old Unzue said the situation surprised him.

"The truth is it came as a shock to me that Messi wanted to leave but, knowing the club and Leo, I understand that he might have very, very important reasons for taking this decision.

"What I was convinced of was that if, in the end, he stayed, he'd give his best and maintain his ambitions.

"[Barcelona coach Ronald] Koeman is managing Messi and the group well, and the situation is not easy, although I think entering a big club that has won titles is harder when they've stopped winning.

"When we arrived with Luis Enrique we did so after a year the team had not won anything.

"That's happening to Koeman now, he's arriving at a messed-up time but if it's not a messed-up time, you don't get the call to become coach of Barcelona."

Barca are languishing in ninth place in La Liga, 12 points adrift of leaders Atletico Madrid after 10 games and six points behind arch rivals Real Madrid albeit with a game in hand.

Causes

The different forms of stroke have different specific causes.

1. Causes of ischemic stroke

Ischemic stroke is the most common form, accounting for around 85 percent of strokes. This type of stroke is caused by blockages or narrowing of the arteries that provide blood to the brain, resulting in ischemia – severely reduced blood flow that damages brain cells.

These blockages are often caused by blood clots, which can form either in the arteries within the brain, or in other blood vessels in the body before being swept through the bloodstream and into narrower arteries within the brain. Fatty deposits within the arteries called plaque can cause clots that result in ischemia.

2. Causes of hemorrhagic stroke

Hemorrhagic strokes are caused by arteries in the brain either leaking blood or bursting open. The leaked blood puts pressure on brain cells and damages them. It also reduces the blood supply reaching the brain tissue after the hemorrhage point. Blood vessels can burst and spill blood within the brain or near the surface of the brain, sending blood into the space between the brain and the skull.

The ruptures can be caused by conditions such as hypertension, trauma, blood-thinning medications, and aneurysms (weaknesses in blood vessel walls).

Intracerebral hemorrhage is the most common type of hemorrhagic stroke and occurs when brain tissue is flooded with blood after an artery in the brain bursts. Subarachnoid hemorrhage is the second type of hemorrhagic stroke and is less common. In this type of stroke, bleeding occurs in an artery in the subarachnoid space – the area between the brain and the thin tissues that cover it.

The best way to prevent a stroke is to address the underlying causes. This is best done by living healthfully, which means:

1. Eating a healthy diet.

2. Maintaining a healthy weight.

3. Exercise regularly.

4. Don’t smoke.

5. Avoiding alcohol or drink moderately.