Using the most accurate numbers I could find, here is the Braves current payroll with only 1 open bench slot open (assuming it will be an OFer):
# Pos Player 2019 Salary
1 C Flowers $4.00
2 1B Freeman $21.36
3 2B Albies $0.55
4 3B Donaldson $23.00
5 SS Swanson $0.55
6 LF Acuna $0.55
7 CF Inciarte $5.70
8 RF Markakis $4.00
9 SP1 Teheran $11.17
10 SP2 Folty $5.48
11 SP3 Gausman $9.35
12 SP4 Newk $0.55
13 SP5 Touki $0.55
14 BN1 Culberson $1.40
15 BN2 Duvall $2.88
16 BN3 Camargo $0.55
17 BN4 Backup OF $0.00
18 BN5 McCann $2.00
19 BP1 O'Day $9.00
20 BP2 Viz $4.80
21 BP3 Freeman $1.58
22 BP4 Venters $2.25
23 BP5 Minter $0.55
24 BP6 Winkler $1.61
25 BP7 Fried $0.55
Total $113.96
That $114M figure could obviously be pared down a bit in a number of ways, but I'm guessing the Braves currently have $10M+ they can use for the 2019 opening day payroll, depending on how much cash they want to hold back for upgrades at the deadline.
I honesty have no idea what AA will do because the roster seems pretty set, but I'm guessing it's either a big trade or a small addition to the bench and maybe a value add to the BP.