He played his first game for Fitzroy, on 24 May 1930 (round four), against St Kilda at the Junction Oval.
It was reported that "Smallhorn … was particularly cool and clever on the wing", in a side that unexpectedly lost to St Kilda 15.18 (118) to 8.10 (58), and that "in Smallhorn they have unearthed a most promising wingster, who in  his first game was their best performer."