I don't know too much of small defenders but there are several names doing well in the VFL / SANFL / WAFL seasons that sprung up in last years draft discussions.
Kobe Ryan playing for Adelaide I think is tearing it up - Midfielder
Ethan Philips was rated highly last year - Key back
Mitch Szybowski as someone else posted above is a chance - Midfielder
Boyd Woodcock at Southpot could be an option, was previously at Port Adelaide - midfielder / small forward
I'm sure we'll be watching our boys closely too. Luke Teal debuted at the weekend, he'll get plenty of chances at VFL between now and the MSD. Lachlan Johnson has looked pretty good this year, maybe gets another chance at it (was drafted in 2019 by the Bombers but never played a game, may have been 1 of those early cuts due to Covid reduced squads) and Mutaz el Nour could be another option.