No, first thing he is head-case and if you are that you will be that whole career and you will not do anything. Second thing, you can't be young all your career. Why Djokovic isn't young than, or Murray, Del Potro? This is his 5th season that he is regular on tour, he has played almost 350 matches, won over 200.
It left just 4 more years (maybe more) for him and his maximum will be to be weeks in top 10 and that's is. Only reason: so fucked up head. He is away to sensibile, that's his problem.
But you never know, maybe something will switch.
there have been times when he's shown great mental strength as well. While its true he had the mental lapses to even get to a 5th set with querrey at wimbledon it also showed tremendous mental strength to grind out that 5th set win. He fell down 15-30 a number of times and never gave a break point
and i never said djokovic and del potro werent young, they are young. All of them are on the younger end of the 20's . Plently of time left for marin to do big things. His style of play is also not as taxing on the body as some of the other guys so he should have longevity on his side