Out of players who are close, Trout probably has the only realistic shot, though even still he needs to double his career HR total to reach 700. If he stays healthy and plays for another 11-12 more seasons averaging between 30-35 HR per season, he has a chance.
Otherwise, the only other bets maybe would be Arenado, Harper and Machado given their age, though even still 700 seems like a very far reach for all three of them. Stanton is at 375 though I don't have any confidence in him returning to an elite HR bat and staying healthy. Though you never know, if Stanton plays until he's 41 or 42 and keeps cranking out 30+ HR's despite other poor offensive numbers for another decade, he might come close.
I think some of the younger bats like Julio Rodríguez or even Vladdy have more of a realistic chance if they stay healthy and crank out 30-40 HR's per season.