The 24-year-old American high-sided off his Kawasaki at the ultra-quick Lukei Heights section of the track and tore an abductor muscle in his groin.
After being taken to a hospital in nearby Melbourne, Hopkins decided to fly home and have further checks.
"It was a hard landing and it felt painful straight away," said Hopkins. "I went to hospital in Melbourne, where the doctors confirmed that I'd torn around 50 per cent of the abductor muscle from the bone. It's not a serious injury, but it's quite painful for the moment.
Stoner quickest on home track
31/01/2008 AT 13:24
"I'm determined to be back on the Kawasaki for the Jerez test, so I'm going home to see Dr Ting and get treatment as soon as possible.
Should he not appear before the season-opening Qatar Grand Prix next month, Hopkins would be the second Moto GP rider ruled out of the rest of pre-season.
Honda's Dani Pedrosa is currently recuperating after suffering a hairline fracture on his right hand following a high-speed crash at Sepang last week.
Season 2008
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Season 2008
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