Walker, who is owned by over 55,000 DT coaches, posted a score of just 24 last weekend against Sydney after managing only one kick and one handball all game.
And Craig admits Walker could be set for the chop with his inconsistent form.
Craig told SA's Nine News, "He’s an exciting player, he’s a talented player but that doesn’t guarantee you a walk up start in our football club.
"You've actually got to perform and there's been times when Taylor's performed very well and there's been other times when he's been very poor."
Should Walker get dropped, it would cause further problems for many DT coaches' forward lines after recent injuries to Simon Goodwin, Matt Pavlich, Jack Ziebell and Daniel Giansiracusa.
In other news from Adelaide, star veteran defender Andrew McLeod ($262k) worryingly picked up a knock at training today and was seen limping before completing the session behind closed doors.
And Craig also acknowledged following Brad Moran's season-ending injury, that young $86k defender Shaun McKernan would probably replace him to make his debut ahead of $86k forward James Sellar this weekend.