Jeff Green has been much improved over the last few months, I've been really impressed. I can honestly say that he might very well be earning his contract, and also be a viable part of the team going forward.
He will never be a top 5 SF in this league, though. James, Durant, and Anthony will still be the top 3 SF's 5 years from now. That leaves two spots.
Rudy Gay is better, and likely will continue to be. Paul George is better already, younger, and will likely only get better. Kawhi Leonard, is also younger, and has a brighter future. Same for Harrison Barnes. Those are just the names off the top of my head that Green has to compete with, I'm sure there are others.
Top 5, not likely. Top 10, real possiblity.