Victoria is closing on the Sheffield Shield title after a dramatic day's play at Junction Oval, punctuated by confusion around an injury substitution.

Reigning champion SA lost five wickets in the evening session on day three of the Shield final, putting the home side in the box seat.

SA limped to stumps at 5-94 in its second innings, an overall lead of only 31 with two days left.

Test keeper Alex Carey was 24no and Shield player of the season Liam Scott had made two.

Victoria was dismissed for 261 at tea and as paceman Sam Elliott prepared on the ground, he pulled up with a hamstring injury.

It clearly caught them unawares, with Mitch Perry hurrying to warm up in the nets at the back of the venue.

Assistant coach Ben Rohrer tried to start the innings as a substitute fielder until Perry was ready, but the umpires would not allow him on the ground.

The Victorians had to scramble for a suitable player, before Perry finally joined the game.

Adding to the drama, Perry trapped SA captain Nathan McSweeney lbw with his first delivery to leave the defending champions reeling at 3-35.

Todd Murphy also claimed a wicket with his first delivery, dismissing Jake Lehmann for one. Lehmann played a terrible pull shot off a nothing ball from the off spinner and edged the ball onto his stumps.

Victorian captain Will Sutherland capped an excellent day by having Jason Sangha caught behind for 34.

Fergus O'Neill and Sutherland had led Victoria's recovery after lunch, wresting the momentum from SA and setting up a first-innings lead of 63.

O'Neill top-scored with an unbeaten 64 from 134 balls, featuring seven fours — his fourth first-class 50.

After missing out on a batting bonus point by three runs, SA can only claim back-to-back Shield titles by winning the final.

AAP