The Brewers were protected from missed time due to injury, career ending injury, or poor performance. They gave all that up for zero cost savings. Zero cost savings, unless Fielder puts together an MVP-caliber season next year and would have filed for 14+ million or something like that. Really, for 5 million in the risk due to the circumstances you listed, the Brewers limited the potential cost if he put together such a season, guaranteed that they'd avoid the unattractive process of an arbitration hearing (with a hard agent to deal with) for 2 years, built goodwill with said agent and player, and gave them cost certainty for the remainder of this offseason and in 2009 as well. Not saying it was absolutely worth it, but I don't think the Brewers reasoning for the deal is all that unclear.