They aren't expected to contend this year anyway. If he's as good as it looks like he is, they need to tie him up for as little money as they can for as long as they can.
But I'm ready to see him play.
This is going to be a very interesting season, both at the MLB level and in the upper minors. Next year's free agent class is one of the strongest ever (Harper, Machado, Donaldson, Blackmon, Kershaw to name a few), and the Braves have positioned themselves to spend big. At the moment, they only have $38M committed to three players for next year, and one of them (Tehran) is likely to be traded before the deadline. At first glance, they would appear to have needs at 3B, OF, and maybe C next year, but if prospects like Riley, Peterson, Pache, and Jackson have strong years, they could fill those holes, allowing the club to spend their money less on needs and more on luxuries- like a pitcher or two to add to their already ridiculous organizational mound depth.