Australia coach McDonald backs stuttering Labuschagne

Batter Marnus Labuschagne is still a key part of Australia's future in test cricket despite failing to impress in their five-wicket defeat to South Africa in the World Test Championship final, coach Andrew McDonald said.

Labuschagne opened alongside Khawaja, scoring 17 runs off 56 balls in the first innings and 22 off 64 in the second, with South Africa completing a remarkable turnaround on Saturday after successfully chasing down an imposing 282-run target.

The 30-year-old has scored one hundred in his last 28 tests and has come away with single-digit tallies in four of his last 11 matches.

"He's a big part of the future of the team. Anyone that averages 45, 46 in test cricket at that age is important. We've got older players there that are closer to the end than the start," McDonald told reporters.

"We've got some younger players that are coming in. If he can get his game in good order for the next four or five years, he can underpin that batting order. But at the moment, he'd be disappointed with the returns. He's missed out on big scores.

"But we're confident that he could return to his best and hence why we keep picking him. And at what point do we stop picking him? I think most players across their journey get dropped at some point in time..."

Khawaja also struggled against South Africa, departing for a duck in the first innings and scoring just six runs in his second, but McDonald said the 38-year-old veteran's presence in the team was invaluable.

"He's on contract, he's an important player. He gives us stability at his best at the top. And we like to look at our players at their best," McDonald said.

"No doubt, a couple of failures here and people then start to talk about maybe it's the end. I don't see an end date with the way he's training, the way he's preparing, the way he's moving."

Australia next travel to the Caribbean for a three-test series against West Indies beginning on June 25.