Boogaard will line up against the Mariners in a trial at Maitland Sportsground on Saturday in his first hit-out since suffering a head knock in the Jets’ opening tour game in Spain earlier this month.

It was the defender’s second bout of concussion in six months. He suffered blurred vision and headaches after the game and sat out Newcastle's next two friendlies in Spain, as well as the 1-0 win over Gold Coast Knights in the FFA Cup.

On returning from Spain, Boogaard consulted Newcastle-based concussion expert, Dr Andrew Gardner.

“I did the cognitive tests in Spain to make sure I was right to fly home,” Boogaard said. “We are lucky to have Andrew Gardner in town, who is one of the world leaders in concussion. We did some more tests and they were all clear; SCAT testing which involves a lot of recall, things like saying numbers backwards and word association memory.”

In a number of professional sports, mainly involving heavy contact, there have been players with a history of concussions who have encountered health issues post career. In some cases debilitating.

At 32 and with a young family, Boogaard was worried about the potential for any long-term effects from his knocks. But any concerns have now been allayed.

“Dr Gardner sat down with me and my wife and put things in perspective,” Boogaard said. “He put my mind at ease to the risks involved. Footballers are obviously not at as high a risk as league or union players. He told us about AFL, rugby league and union players who have had 30-plus concussions. They are in their 60s and have had no signs. To hear that puts my mind at ease. It doesn’t mean I am going to run around and throw my head at everything. But I can still play the way I have always played.”

Boogaard has suffered six concussions, including two major “black outs”  in a 217-game, 12-year A-League career.

“I had blurred vision and the loss of feeling in my hands in Spain,” Boogaard said. “I was light sensitive and had headaches. I didn’t black out, which are the scary ones.

“The first concussion I had was playing for the Mariners against Newcastle up here,” Boogaard recalled.

“[Jets midfielder] Noel Spencer hit a diagonal ball that hit me flush on the temple. I was out cold.

“I have had a couple of big ones where I have blacked out and can’t remember.

“The last one was a head-on-head collision. They have either been head-on-head or a result of my head hitting the ground.

“One of the early ones, it took me a month to come back from it. I would get reoccurring headaches and was dizzy at training. It was pretty serious.”

A-League protocols around head knocks and concussions have risen significantly in recent years. Contact sports, in particular, have become increasingly stringent.

There have been a number of studies done about the impacts of constantly heading a football, especially children and women.

Dr Gardner, a clinical neuropsychologist, has researched sport-related concussion for nearly a decade, specifically the diagnosis, assessment and management as well as examining the longer-term issues.

“Andrew is a leader in the field,” Boogaard said. “To actually pinpoint it [health issues] on just concussion is quite hard. There are so many other things that can contribute.

“Lifestyle choices play a massive factor. He has seen league and union players who have had a pretty heavy concussion career, and post career have cleaned up their diet and cut back drinking alcohol and those symptoms have gone away.

“There are a lot of lifestyle things that go along with it. It is not just concussion.”

Jets coach Ernie Merrick worked at the Victorian Institute of Sport before the A-League and has been involved in research and discussion panels around concussion and football over a number of years.

“I am not a medical person but I have been involved in research in that area,” Merrick said.

“The days of a big heavy soccer ball which soaked up the water and was like a ton of bricks are gone. “The balls are much lighter and heading is not as big a part of the game as it was.

“But we certainly have to be mindful of concussions and we certainly are.”

Boogaard said the hit out against the Mariners was timely ahead of the FFA Cup battle with Melbourne City at AAMI Park on Wednesday.

“It will be good for us to play another A-League team to see where we are at,” Boogaard said.

“The Mariners have had a big change in coach and playing personnel. They will be a different outfit to previously. It will be another good test, a marker for us to see where we are at.”

The Jets win over the Gold Coast was their first in four attempts at the Cup.

“It is good that there is so much emphasis now on doing well in it,” he said. “It’s a great competition and makes a long arduous pre-season enjoyable when you have that focus every fortnight to play in a Cup game.

“Hopefully we can do something special and go a bit further in it.”