The two-time Olympic Champion was unwell when he finished fourth on his return to action at IRONMAN 70.3 Oceanside in April following ankle surgery.
The British star was then forced to pull out of the IRONMAN World Championship in St George earlier this month due to illness.
Now comes a fresh blow for the Yorkshireman, with a stress response in his hip meaning he will miss the massive showdown with the Norwegian star on Sunday.
“Honestly, I’m devastated, said Brownlee. ‘I was frustrated to miss St George, and now this. I’m gutted. I was so invested in the process and loved working with my team. This was the goal that stimulated me again in the sport, on par with the Olympics. I’ll do what I can to support Joe.”
“We are extremely disappointed with the announcement, but when you are pushing your body to the limit like Alistair has been, it’s a fine line,” said two-time Kona king Chris McCormack – one of the driving forces behind the event.
“Alistair is a true professional and will be there to support Joe, who has been preparing for IRONMAN Nice at the end of June, so in good shape to take on the challenge.’’
Blu won’t take Skipper lightly
Blummenfelt meanwhile, riding the crest of a wave after that St George success, said: “It’s not going to get easier with Joe. He has a better full-distance resume and a higher world ranking than Alistair. I’m looking forward to the challenge.”
Brownlee will support Skipper by pacing him in the swim, and will also join the commentary team for the live broadcast.
Brownlee replaces Richard Varga on Skipper’s team, with Jonny Brownlee also dropping out to be replaced by German national marathon champion Frank Schauer. Skipper retains the support of the bike pacemaking team led by Alex Dowsett, who is fresh off riding in the Giro d’Italia.