The senior batsmen were dismissed in the space of five overs on a rain-shortened first day of the Boxing Day Test, leaving Pakistan on 142 for 4 when play was stopped shortly before tea.
Younis underwent a stern examination by Josh Hazlewood and Jackson Bird, the former thinking he had Younis lbw when he was on 3, only for the decision to be overturned on review. Another lbw appeal four overs later was turned down, as Younis went through a 26-ball scoreless spell. He settled after the afternoon drinks break, only for Bird to find a gap through his defence to dismiss him for 21.
Misbah fell to the same bowler, a brief 13-ball stay which was difficult to present as any kind of a form guide.
The dismissals continued a run of low scores for both; Younis now averages 12.75 from his last eight innings and Misbah 22.43 from his last seven. Both have a solitary half-century in that run, and Younis' did come in his last innings in Brisbane.
Given their ages, however, pressure will mount quickly on both, especially if results do not go Pakistan's way.
"Only they would know [what the future holds]," Arthur said. "But we back them massively in the dressing room. That's all I can say. Ultimately they will decide when they think the time is right.
"But within our dressing room they are held in such high esteem and we back them every time they go out and play. There's no doubt in our dressing room about Younis and Misbah.
Arthur said the pair had earned the right to go when they felt it was time. "One's been an inspirational leader for the last six years and the other guy is closing in on 10,000 Test runs. They've earned the right in a massive way. And again the esteem they are held in within the dressing room is second to none."
The situation Pakistan want to avoid is both leaving at the same time. The conversation about Misbah's future, in particular, has been going for some time. Though he has refused to be drawn on whether this is his last series, Pakistan are not scheduled to play another Test series until March next year, when they travel to the West Indies. Misbah will be nearly 43 then.
Younis, 39, has not spoken of his future plans in any definitive sense. He has often expressed his ambition to become the first Pakistan batsman to 10,000 Test runs, a landmark that remains 235 runs away.
Arthur said, in an ideal world, he would want them to stagger their exits so that the impact on younger batsmen in the side can be more carefully managed. The pair has had a significant influence on the progress on more junior partners, including Azhar Ali and Asad Shafiq.
"Yeah, I mean in an ideal world, you will," Arthur said about staggering their exits. "But ultimately that decision rests with them. They've earned the right so if they want to continue, fantastic, because that's what we want as a cricket team. If they don't, we feel we are starting to make enough ground in terms of bringing other players through.
"I want to reiterate there's no doubt surrounding those two whatsoever. They are still model professionals and they train, they are fit, they practice and they are inspirational around the dressing room. The longer they can be around that dressing room the better it is for the Sami Aslams, the Babar Azams, the Azhar Alis, the Sharjeels, the young guys who are with us."