Mabil - absent from the Australia set-up for the best part of two years - has not featured under Popovic's tenure but has been called up for March's friendly window against Cameron and Curacao.
It's a reward for a return to form in Spain's second division where the 30-year-old forward has two goals and four assists in 23 games to help put Castellon in fifth spot.
Geria has endured a similar international experience, having been overlooked under Graham Arnold before becoming a mainstay of Popovic's set-up over the last 18 months.
"Awer, it's really a credit to him and how he's been performing in Spain and his approach to not being involved for two years," Geria said in Sydney on Sunday.
"It's not easy to mentally keep going and believing you can be involved.
"But he's put his head down, and he's worked really hard, and is doing really well in Spain.
"He's really earned this call-up for this camp and I'm sure he's going to take his opportunity as well."
Geria, who worked under Popovic at Melbourne Victory, knows the Socceroos boss will pick a World Cup squad on merit.
Popovic has preached the need for his players to be on top of their game every week and maintain "elite" standards of performance and preparation.
"He is watching everything that you do," Geria said.
"I think if I was to come to the other end of this July and I wasn't involved, I'd want to be able to look myself in the mirror knowing that I did everything that I could to be there.
"I know if I cut corners, or if I didn't do everything that I could - recovery, diet, sleep, whatever - and things didn't go my way, that would be something that's regret."
Geria has mainly been used as a right-sided centreback as part of Popovic's back five but could be in line to see gametime at wingback in the next week's games in Sydney on Friday and in Melbourne four days later.
Blackburn's Lewis Miller was a lock for that wingback role until he ruptured his achilles.
"I'm a bit older now, I'm not 23 anymore," said Geria, 32.
"Over qualifying, I did fill in there a few times coming on the substitute.
"I guess it is position that I do know how to play and if they need me to fill in there that's fine."
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