Wolves striker Chris Iwelumo suffered a broken metatarsal in his side's 1-0 pre-season win over Perth Glory.
Sylvan Ebanks-Blake scored the only goal of the match in the second minute as Wolves kicked off their tour of Australia with a win, but it came at a cost with the injury to Iwelumo.
Iwelumo was involved in Wolves' goal as he flicked on a throw-in from George Elokobi to Ebanks-Blake, who took two attempts to slip it over the line in a goalmouth scramble.
Scottish international Iwelumo was forced off early in the first half with the foot injury following a tangle of legs with new former Leeds man Jacob Burns.
Wolves have revealed Iwelumo sustained a broken metatarsal in the tangle and he now looks certain to miss the start of the Premier League season.
"It's disappointing for me and for the team and for the club, but for Chris somebody who has worked so hard and done so well for us he is going to miss out on the start of the Premiership, so it is bitterly disappointing for him," said McCarthy.
The game saw Wolves' record signing Kevin Doyle make his debut as a second half substitute.