Last November, a man was arrested on suspicion of manslaughter over the incident and has been re-bailed until next month.
But one of Johnson’s former team-mates, Victor Bjorkung, is frustrated by the time the investigation has taken.
“The whole police investigation, I think it’s been taking way too long, for Adam’s family and everyone involved in the whole thing,” he said.
“But I understand why as well, nothing like this has ever happened before. So it’s not an easy black or white, this is right and this is wrong.”
In response, South Yorkshire Police said: “In the year since the incident, we have been working meticulously to fully investigate the unprecedented circumstances in which Adam sadly lost his life.
“This is a complex investigation which has involved conversations with highly specialised experts in their field.
“Our work is continuing, and we are working closely with the Crown Prosecution Service.”
Since Johnson’s death, safety changes have been made in the sport.
The new International Ice Hockey Federation (IIHF) rulebook for global hockey, as of the 2024/25 season, stipulates neck guards are mandatory in all IIHF-affiliated leagues.
Since 1 January, 2024, neck guards have been mandatory in the Elite League.
However, they are not mandatory in the National Hockey League (NHL).
Bjorkung added: “We are moving forward slowly, but I think it has to come to the top league, the NHL, as well – where they put their neck guards on and show the younger kids that it is cool to wear one, it is cool to be safe, rather than not wear one and try to look a certain way. It is cooler to be safe in my opinion.”