Diagnosed last September, the 41-year-old father of four, including baby Harry, fought a courageous battle against the illness before finally succumbing in the early hours of yesterday morning.
News of his death was revealed to Munster players and management yesterday as they assembled for stage two of the cycle.
The opening leg, involving a 98km cycle from Musgrave to Thomond Park on Sunday, was attended by his wife Lyndsay.
The full Munster academy, as well as 22 senior players, will finish the Irish stages in Trinity College today, before moving over to the UK, finishing in his home town of Warrington on Thursday.
Some of the money from a variety of fundraising activities will fund research into Motor Neurone Disease being carried out in Trinity by Professor of Neurology Orla Hardiman.
A native of Wigan in the north of England, Paul played almost all his professional rugby league career with Warrington Wolves.
Before his move to Munster in 2007, he had been an assistant to four successive Wolves head coaches.
As a player, he made his name as a tenacious tackler and aggressive ball carrier.
Married to Lyndsay, they have four children; Ella (13), Georgia (11), Jack (7) and baby Harry, born last October. Paul’s father also died from the disease.
Paul stated recently he was devastated when first diagnosed. A few months before his death, he lost two stone in weight, had difficulty eating and had to use a wheelchair.
“I’d like to express my sincere thanks to my close friends at home and in Ireland who have been there for us. The staff and players at Munster have been fantastic and have given me every help and support I could wish for. They’re a real family over there, which is why they are so successful and I can’t thank them enough,” he said.
One poignant moment in the midst of all the jubilation marking Munster’s third Magners League trophy summed up the respect in which he was held by the entire panel.
Munster out-half Ronan O’Gara wheeled him over to the podium where captain Paul O’Connell presented him with the cup during the after-match celebrations in Thomond Park.
“Darbs” as he was affectionately known, was told that he would not be able to attend any more Munster games a few months ago.
But Munster’s new forwards coach Anthony Foley said this was never going to be the case as Paul went to considerable effort to attend the semi-final and final.
The last time Darbyshire worked with Munster was back in September when Leinster defeated their arch rivals 13-9 in the Aviva Stadium.
Munster manager Shaun Payne revealed Paul’s presence on the sideline was another driving force that helped the men in Red succeed against the odds.
“Paul had gone back to Warrington to be with his family.
“He made a massive effort to attend the semi-final and final. It meant a massive amount to us. It was almost like we had to do it for Paul, to be honest,” he recalls.
Munster prop John Hayes agrees it was an added motivation for Munster players, who knew this was their last game of the season and were aware of forthcoming fundraising for their former coach.
“Paul was on the sideline in a wheelchair when we were going in and out at half time. You could see him there. You wanted to do it for him,” he recalls.