I know some people that know some people, and the scuttlebutt was the Brewers were looking to move Jean Segura from Day 1 of the offseason. They finally accomplished that goal on January 30th when they sent him and RHP Ty Wagner to Arizona for RHP Chase Anderson, SS Isan Diaz, and 2B/3B Aaron Hill. Diaz was the jewel of the deal but the only way the Brewers were able to get him was by taking on $5.5 million of Hill's salary. But he'll serve as the regular third baseman out of the gates and it's not impossible for the Brewers to squeeze even more value out of that trade.
At one point he was one of the best second basemen in baseball. But at 34 years old Aaron Hill's best days are behind him (I refuse to make an over-the-hill joke!). That means we cannot expect him to return to his best self. He hasn't hit 20+ home runs since 2012. He did look good in 2013, but he only played in 87 games due to injuries including a broken hand. The last two seasons were the two worst of his career: 78 and 71 wRC+ respectively.
If you want to look for hope you might be able to find it in his 2010 and 2011 campaigns. Those were his other two worst seasons: 77 wRC+ in each year. He followed those seasons up with a 5+ fWAR in 2012 and a 124 wRC+ in 2013. Can he do it again? Can he figure things out and have a rebound season like he did in the past? Or is this just a case of an older player flaming out? I honestly don't know.
I looked at his zone profile and I don't see a ton of change. His swinging strike rate, swing rate, and contact rate were are right around his career numbers over the last two years. He did swing at fewer balls out of the zone last year which you'd think would lead to better results. But that wasn't the case. It probably had something to do with a sharp spike in his ground ball rate. His line drive rate and fly ball rate dipped sharply last year too. If that's the start of a trend it's a big problem. If it's an anomaly then returning to more normal rates could mean an increase in offense.
For what it's worth ZiPS and PECOTA expect Hill to be slightly better than he was the last two years:
That's still below average production (100 wRC+ and .260 TAv are considered league average). But look back to last year and the Aramis Ramirez traded. He was hitting 247/295/430 when the Brewers traded him. That was equivalent to a 90 wRC+ and a .251 TAv. That's pretty much exactly what the two projection systems expect Hill to hit. And he has two advantages over Ramirez. He's making less than half the salary and he can play second base in addition to third.
Last year the Brewers got Yhonathan Barrios in exchange for Aramis Ramirez. Unless Hill really tanks, I think there's a good chance the Brewers can complete a comparable trade this year. It's probably won't end up a big traded, but every team needs 25 players. And if you can get a solid player on the peripheral this way, and save a few million you might have otherwise paid on the free agent market, it starts to add up. This is the upside for Aaron Hill in 2016.