Almost all businesses operate on a budget, usually annual. Braun's salary in future seasons will be a part of that budget, unless it gets moved sooner as a "prepaid expense". If the Brewers pay it earlier then they would discount that for the time value of money - it wouldn't cost "millions more". Discounting $19M (2019 salary) for two years at 5% per year yields a net present value of ~$17,200,000, or a difference of $1.76M. If you were to offer to split that with Braun evenly it would cost $880K, and I'm sure Braun would jump at it. Discounting Braun's 2020 salary ($17M) by three years at 5%/year yields $14,685,000 net present value. I don't think the OP was intending to entirely pre-pay it, but to front-load some of it so the future salaries (that will count against future budgets) will be reduced, allowing for the addition of more players/salary expense in those future season's budgets.