Former Australia captain Aaron Finch is worried about Marnus Labuschagne's form ahead of the World Test Championship finale against South Africa.

As things stand, the team management can even drop him from the playing XI if they prefer Sam Konstas ahead of the veteran. With Cameron Green set to make his return, there's only room for either Konstas or Labuschagne in the playing XI.

In case Konstas sits out, the opening order needs to be altered, and Australia might hesitate, which would force Labuschagne to sit out. Finch pointed out that the Klerksdorp-born hasn't scored enough runs at number three and has failed to put any pressure on the opponent in the last 18 months.

"It's a difficult one because Marnus hasn't scored the runs at No. 3 and the way that he's been playing has probably been the concern for me. I mean his strike rate has plummeted over the last 18 months. He is not putting any pressure back on the opposition at all. And when you're batting in that position, you have to be prepared to counterattack at certain times," Finch told ESPNcricinfo.

"You can't just allow the best bowlers in the world to bowl with a new ball at you over and over without forcing their hand a little bit. You're going to get a good one. We've seen wickets around the world have probably been better for fast bowling over the last couple of years, so you can't afford to just sit there and wait to score," he added.

Against India in late last year, Labuschagne struggled heavily against Jasprit Bumrah as he almost came to a standstill. In the Perth Test, he scored only two off 52 balls and in Brisbane, 12 off 52. In modern times, when the nature of Test cricket is changing, Finch is also worried about the poor strike rate.