One Marsh brother has been recalled to the Test team but the other has been warned he needs to perform in Adelaide next week or risk losing his place.
Shaun Marsh was rewarded for his solid form for WA this season and his Test experience over the past four years when he was called up to replace the injured Usman Khawaja in the third Test. 
But Mitch Marsh is on a final warning after scoring just 85 runs at an average of 12 in five Tests this year.
Coach Darren Lehmann confirmed yesterday that Mitch Marsh's lively seam bowling meant Australia would consider adding second spinner Stephen O'Keefe to the team to take on New Zealand in the day-night Test match at Adelaide Oval which begins next Friday. But Lehmann would not guarantee the all-rounder's place beyond the New Zealand series.
"He has to make runs," Lehmann said.
 "His bowling is no dramas at all but we want him to put some more runs on the board.
"He batted quite well in the first innings (with 34 at the WACA Ground) but you need to perform at No.6."
The brothers have already played one Test together, in Brisbane last summer.
When asked if veteran paceman Peter Siddle would replace the retired Mitchell Johnson in Adelaide, Lehmann said: "You would think so. Guys like Peter Siddle again get an opportunity to play."
Returning speedster James Pattinson was named in the 13-man squad after a 20-month absence but it appears that he will not be considered until the West Indies series next month.
A New Zealand victory in Adelaide would extend their undefeated record to eight series over two years, with coach Mike Hesson confident the improved performance in the second Test augured well for his team.
"It showed that when we're on song we're certainly the equal, if not better than our opposition," Hesson said.
Lehmann said O'Keefe, the NSW left-armer, had been added to the squad because of his good record in the Sheffield Shield and the possibility two spinners could be used on the drop-in Adelaide pitch.
That would give Mitch Marsh greater responsibility as the third seamer.
 "We have to have faith in Mitch Marsh's bowling if we're going to (pick O'Keefe)," Lehmann said.
"We'll just have to wait and see what the wicket is like but that's a real option for us."
Cricket Australia have flagged that Josh Hazlewood may be rested too, despite bowling just 129 overs since the end of the Ashes in   August.
Like numerous current and former players, Lehmann was critical of the flat WACA pitch. 
"You probably want more pace, in particular talking about the WACA because it certainly wasn't a normal WACA pitch," he said.
"They might have got the preparation wrong. 
"We don't have too much input into wickets. 
"That's one of the pleasing things about us as a nation, that the curators make the pitches."
 Lehmann said the constant replacement of damaged cricket balls during the match was also frustrating.