The 30-year-old, capped 125 times since making his debut in 2005, took a break from representing the Albiceleste two years ago before making a swift U-turn.
Messi had grown frustrated at his treatment from the local media, having been criticised for repeated near misses at major tournaments - including four years ago when losing to Germany in the World Cup final.
Ahead of this summer's tournament, the five-time Ballon d'Or winner admits that walking away for good is something that he is considering.
"It will depend how we do, how it ends," he told Sport. "The fact we've lost three finals now has led to some complicated moments with the Argentine press due to the differences in seeing what it means to reach a final.
"It is not easy and [reaching three finals] has to be appreciated. It's true that winning them is important, but getting there is not easy."
Two-time tournament winners Argentina face Iceland, Croatia and Nigeria in the group stage.