I mean I am completely shooting from the hip but I would suspect that McHenry is Fekitoa cover for when he's away with Tonga too and that he's out until Christmas. He's 6ft 2 and 95kg so a little light maybe but offers good option. I'd reckon Costello probably has seen something that Blackett might like because we have links with him.
Patrick Harrison is 5ft 10 but 111kg and was the youngest hooker in Edinburgh history and 3rd youngest in PRO14 history. Must be a fairly useful talent.
So we now have the following available
HKR: Frost, Eckersley (Harrison)
Second Row: Stooke, Fifita, Cardall, De Chaves
Centre: Gopps, Le Booj, Simmonds, McHenry
A little more cover than we had before.