Walsh’s World Championships gold medal was the first ever for a man from New Zealand and the 25-year-old said he had been battling the groin injury when he threw 22.
03 metres to clinch it on Monday.
“I’ve got a seven centimetre tear in my groin, and that pretty much means some time off from competing to rehab and repair,” Walsh told Fairfax Media on Thursday.
“I’ve got some training to do in the next wee while to test out if it’s any good or not, and we’ll go from there.”
The Rio Olympics bronze medallist suffered the injury in his final training session before he went out to top qualifying with a season best throw of 22.14m.
The Christchurch-based builder was limping noticeably after winning the title and said he would need a scan to determine the extent of the injury.
He had the scan in Britain on Wednesday and said he would now have to adjust his schedule as he sought a lucrative payday in the Diamond League.
“I’m meant to be doing five comps, but I will now not be able to do all five,” he added.
“My first competition may be touch and go for the Birmingham Diamond League on August 20 but I will definitely be able to compete in Zagreb (Aug. 29) and the Diamond League final in Brussels (Sept. 1).”
Walsh is second in the Diamond League on 14 points behind American Olympic champion Ryan Crouser, who leads on 24, with the overall winner of the series pocketing $50,000.
Walsh earned $60,000 by winning the world title and said any additional prize money would be a big factor in keeping him going throughout the year.
“There is a long time between drinks, so to speak,” he said.
“It is a costly business I’m in. I’m lucky that I get supported by the government pretty well and by Athletics NZ.
“It does make things slightly easier, but it’s also good to make a bit more money if I can as well.”
(Reporting by Greg Stutchbury; Editing by Nick Mulvenney)