http://www.afl.com.au/news/2015-06-04/knee-surgery-to-end-beams-year-early-again
AFL Media hinting it may be Bourke & Beasley.
Bourke played all his Jnr footy as a Forward, and at this stage he would be a better option forward than Hammelmann.
If this is what happens & McStay is back, then maybe as a Defender ?
My impression is that Whiting usually gets pretty solid info from the club, so I'd say Bourke and Beasley are more likely.