The Brewers need some trade bait. The Brewers have two starting-caliber third basemen. With that in mind, here are three likely options. I'm leaving out options like "Trade both for Greg Acquino and start Seth McClung at third."
1) Trade Mat Gamel for/ in a package for a starting pitcher, let Casey McGehee be the 3B
2) Keep Mat Gamel and Casey McGehee
- McGehee produces like an average-ish 3B, Gamel sits in AAA and is eventually traded
- McGehee produces like he has in every year before 2009, goes back to the bench, Gamel starts
3) Trade Casey McGehee for/ in a package for a starting pitcher, let Mat Gamel be the 3B
The tricky thing is that we are not sure of McGehee and Gamel's value on the trade market. I would expect that Gamel would have more value. He should have more value. But some general managers are not great at evaluating players, and might look at McGehee's .367 wOBA in 394 plate appearances and decent defensive scouting reputation as a better get than Gamel, who was given inconsistent playing time despite putting up a league-average batting line and .330 wOBA in 148 plate appearances. Towards the end of the season, the Brewer management criticized Gamel's approach and ability. When starting at a defensive position, McGehee's OPS was .870, Gamel's was .864. There is a pinch hitting/ DHing penalty that lowers a player's expected level of performance when hitting in those situations.
As so I think it sets up perfectly for option number 3, which is my endorsement, though I am certainly willing to listen to arguments for another option. McGehee's value will never be higher. Gamel's value will probably never be lower. McGehee is a utility player coming off a career year, and Gamel is a stud prospect who had a decent year-- made to look worse by improper evaluation, like only looking at his strikeouts and deflating his batting stats by using him as a pinch-hitter and DH.
What should we logically project from McGehee for next year-- something like .280/.330/.450 with -5ish defense? That's a major league starter, probably close to league-average. I would project Gamel, next year, for something very similar. Maybe a slightly better hitting line and slightly worse defensive line. But they're looking pretty similar. And I would think that most would agree with me that Gamel has a higher chance to be a star next year and in the next 6 years. And on the opposite side McGehee probably has a larger chance to perform closer to his .279/.332/.409 career line in the minor leagues.
There are legitimate concerns about Gamel. Everyone's skeptical of his defense but there have been good signs so far. His strikeouts last season in the majors are a problem, but he managed to produce at about the league average despite that problem. And: 150 plate appearances.
If I had to choose one player to be the starting third basemen from this day until 2015, which is how long both players are under Brewer control, I would easily choose Gamel. And considering that McGehee probably has good value on the trade market, it's a no-brainer decision for me.
Baseball management is all about managing assets and maximizing value. It's the simple concept of selling high and buying low. The Brewers have lowered Gamel's value and raised McGehee's-- let's see if they follow through and maximize what they did to use McGehee as a tool to improve the pitching staff.