The former deputy prime minister is no longer attending party room meetings amid rampant speculation he plans to defect to One Nation.
Nationals backbencher and former leader Michael McCormack said while Mr Joyce would make his decision in due course, he hoped it would happen quickly.
"I'd like to think that'll be very, very soon," he told reporters in Canberra on Tuesday.
"We've got another party room meeting next Monday."
Mr McCormack was also hopeful Mr Joyce would return to the fray.
The two former leaders have had a rocky on-again, off-again relationship, with Mr Joyce rolling Mr McCormack for the party leadership in 2021.
The pair have since become unlikely allies following the coalition's recent election defeat, urging their colleagues to walk away from any commitment to net zero emissions by 2050.
The issue is now threatening to split the coalition as Mr Joyce considers whether to join Pauline Hanson's One Nation.
The former deputy prime minister has also cited his ruinous relationship with Nationals leader David Littleproud as a reason for the divorce.
Nationals senator Matt Canavan said he hoped Mr Joyce and Mr Littleproud could reconcile their differences quickly after the pair held a brief meeting on Monday.
"I think it's a good thing that David's reached out to him, and I hope they can repair that," he told AAP.
"As I say, family is much stronger when it stays together and hopefully we can do that."
The party's disunity has further diminished the coalition's prospects of chipping away at Labor's commanding parliamentary majority at a time when the Nationals would like to be applying scrutiny on the government over high energy costs.
With senate colleague Ross Cadell, Senator Canavan has been conducting a review into the Nationals' net-zero position and presented details of the report to Monday's partyroom meeting, which Mr Joyce did not attend.
"I would have loved to have Barnaby in our room today. It is disappointing that he's not attending meetings," Senator Canavan said.
"I'd love to see him back sooner rather than later."
Despite Mr Joyce's protestations against the target, the coalition is yet to recommit to support for net zero by 2050.
Senator Canavan is dead against net zero, while the man leading the Liberal energy review, Dan Tehan, said bringing energy prices down in the short term was more important than lowering emissions over the long-term.
"What we have to focus on ... is what's happening in the next five years, what's happening to electricity prices, what's happening with Labor's reckless renewable rollout, how do we fix that," Mr Tehan told Sky News.
He backed nuclear energy and accelerating gas exploration approvals to help get power bills down, ahead of a full backbench meeting on Friday to further discuss his policy review.