HAWTHORN is resigned to losing prized recruit James Frawley for "some time" after he sustained a right pectoral injury in the Hawks' gripping two-point loss to Essendon on Sunday.

In just his second game since his high-profile free agency switch from Melbourne, Frawley had to be substituted in the first quarter after hurting himself in a tackle. 

It is not the first time the 26-year-old defender has suffered a pectoral issue – his 2011 pre-season was affected by a similar injury – and Frawley appears set for a stint on the sidelines. 

"All we know is he's got a pec injury and we just need to establish the seriousness by scan tomorrow," coach Alastair Clarkson said post-match.

"It was obviously serious enough for him to be subbed out of the game. He'll miss some time but we're just not certain, until we get it investigated tomorrow, just how serious it is.

"Frawley's injury left the Hawks exposed for key defensive options against Essendon tall tall timber Joe Daniher (three goals) and Jake Carlisle (two).

The Hawks were already missing another All Australian backman, Josh Gibson (soreness), and clearly lacked star midfielder Sam Mitchell's composure after he was a late withdrawal with a corked calf.

Clarkson hoped the pair would be available to take on the Western Bulldogs in Launceston in round three.

"Both (Gibson) and Mitch didn't recover as well as we would have liked out of the Monday game (against Geelong) and six-day break," he said.

"We're hopeful that both those guys will be OK. They were both touch and go. "We've taken the attitude to play fresh blokes early in the season.

"Taking two All Australians out with late withdrawals doesn't help too much, but our history has been that we usually replace them with fresh guys who were ready to play and run out the game.

"It just didn't work for us today, but in most instances it does.

"The Hawks have further key-position options if required with Ryan Schoenmakers and Matt Spangher, who played his first match of the season for Box Hill on Saturday after a niggling calf complaint.