Presuming that Larnach's issue is minor, I think Kirilloff is very much on trial right now. If his power is sapped or if he can't be available all of the time, I think they'll option him or put him on the Injured List again.
Larnach has shown for now he deserves to stay. Gordon is a utility guy who can't be optioned, Fortunately for Kirilloff, there are at-bats to be had at first base. If Kirilloff can't perform, Miranda and Arraez would take those at-bats.