When Luai asked to change his flight out of Townsville following last week's loss to North Queensland, Marshall was unaware his star player would be travelling to his future home country to attend a golf tournament.
The trip came only days after Pepsi unveiled Luai as a brand ambassador ahead of his arrival at the Chiefs for their first NRL season in 2028.
Luai's trip to Port Moresby, and the first of what is likely to be many promotional opportunities with PNG brands, come while he remains on a seven-figure salary with the Tigers.
The five-eighth will also join Parramatta on a one-year deal before his first pre-season with the Chiefs, which begins in more than a year.
Marshall described media concerns over the optics of Luai's enthusiastic PNG links as "irrelevant to me".
"He paid to change his flights (from Townsville) and not come back with us, which happens quite often with players," Marshall said.
"From my opinion, it's his time off.
"What he chooses to do in his time off, that's up to him. In one week's time, he's not going to be here anymore and we're not going to have to worry about any of those things."
Marshall said, in time, Luai's move to the Chiefs could help transform him from villain to hero in the public's eye.
"He always gets painted as the villain for some reason," Marshall said.
"But he's about to walk into a country in about 12 months' time where he's about to be the hero, so it's going to change for him."
Four-time premiership winner Luai arrived at the Tigers last year with hopes of finally reinvigorating the long-struggling joint venture.
Instead, Luai's decision to sign with the Chiefs coincided with a sharp downturn in form that consigned the Tigers to a 15th consecutive year out of finals.
Marshall previously admitted he had let the saga become a distraction for the 15th-placed Tigers, who had been in the top four when Luai signed with the Chiefs.
"There's obviously a lot of things probably both sides wish went a little bit better, but we are where we are and we've got to move forward," Marshall said.
Marshall still believed Luai's signing was a success for the Tigers, who face top-two side Penrith in their last game of the season.
"There's no regrets from our side about bringing him here whatsoever because he did the job we needed him to," he said.
"I'm sure a lot of people probably have their opinions about what he hasn't done here, but all I've seen are the things he has done here and the impact he has had on the club.
"I'm sure he would admit himself that he would have liked to have contributed more on field performance-wise but all in all, he'll leave here having had an impact on our club."
13°C