Following the deaths of Lisbon Lions Billy McNeill and Stevie Chalmers, football cannot be allowed to ignore growing evidence about the risk of brain injury to players, writes Martyn McLaughlin.

With the loss of Billy McNeill and Stevie Chalmers within the space of a week, Scottish football has been robbed of two of its heroes. Their remarkable achievement as part of the Lisbon Lions – a group of young, working class men, all but one of whom were both within a 10-mile radius of Celtic Park – will forever remain one of the cornerstones of Scottish footballing folklore.

Overnight, the names of those who conquered the might of Europe assumed a place in the history books. They inspired subsequent generations of players and managers, but just as importantly, they nourished ordinary punters who saw in Jock Stein’s players something of themselves. The significance of that gift cannot be understated. It showed how even amid the soot and stoor of post-war Glasgow, flowers could emerge through the cracks.

Deaths of Lisbon Lions Billy McNeill and Stevie Chalmers are a call to action – Martyn McLaughlin