"But he's certainly given my eardrums a bit of a bashing over his availability."
Halfback Brad Weber (neck) and first five Josh Ioane (ribs) are the other injured frontline players set to be available again in Melbourne. But Retallick's recall would be especially pleasing for a side who spent the past two seasons without his services.
The 30-year-old returned to Super Rugby this year after a stint in Japan with the Kobelco Kobe Steelers, featuring in only the first six of weeks of the competition before injury struck.
McMillan said the damaged thumb had limited Retallick in contact training but the 90-test veteran had been doing plenty of work to keep fit.
"He's doing a fair bit of running but I'm not sure how it's impacted his weight," the coach said. "I heard somebody the other day say he's at a real healthy weight, not down to where he was in Japan.
"He knows how to hit the ground running so when he gets back on the field I imagine it won't take him too long to get back up to speed."
Retallick's return to action will be a major boost for a Chiefs team sitting in fourth ahead of tomorrow's clash with the second-placed Brumbies. They will round out the regular season with matches against the lowly Rebels, Force and Fijian Drua, with their eyes firmly fixed on a home quarter-final.
McMillan's side will however be without the services of prop Sione Mafileo (neck) and loose forward Simon Parker (shoulder), with injuries ending their seasons.
Chiefs v Brumbies
Saturday, 7.05pm, Hamilton
Chiefs: Kaleb Trask, Jonah Lowe, Alex Nankivell, Quinn Tupaea, Etene Nanai-Seturo, Bryn Gatland, Cortez Ratima, Pita Gus Sowakula, Sam Cane (c), Luke Jacobson, Tupou Vaa'i, Josh Lord, Angus Ta'avao, Samisoni Taukei'aho, Aidan Ross.
Reserves: Bradley Slater, Ollie Norris, Atu Moli, Naitoa Ah Kuoi, Samipeni Finau, Xavier Roe, Rameka Poihipi, Emoni Narawa.