Multiple third basemen were involved in trades in July last year, as the Diamondbacks added Chris Johnson, the Rays picked up Ryan Roberts, and the Yankees traded for Casey McGehee. The Astros acquired current starter Matt Dominguez from the Marlins, who themselves added Zack Cox from the Cardinals later that month. The Cubs acquired a third base prospect as well, getting Christian Villanueva from the Rangers.
This year, contenders such as the Yankees, Dodgers, Indians, and Red Sox could be in the market for help at the hot corner. Here's a look at the potentially available players.
Starters
Chase Headley (Padres), Aramis Ramirez (Brewers), Michael Young (Phillies), Alberto Callaspo (Angels)
It's been made pretty clear by this point that the Padres don't intend to trade Headley, and would like to talk about an extension during or after the season. Still, it's hard to ignore the Padres dropping nine straight and Headley's solid play since the end of his abysmal June. GM Josh Byrnes would surely at least listen to offers this month, wouldn't he?
Ramirez, also one of last year's best offensive third basemen, does seem eminently available. There are three problems with that. One, he's 35 and may be slipping defensively, perhaps to the point where an AL team wouldn't expect or want him at the hot corner for all of next year. Two, he's under contract for 2014. That's not necessarily a problem until you see that he'll earn a $16MM salary plus a $4MM buyout on a mutual option, essentially making him a $20MM player next year (not counting a discount for deferred money). Ramirez has shown repeatedly that he can provide $20MM worth of value. However, bringing us to our third issue, he's slugging just .414 this year. That may be nothing more than a month-long slump, but the timing isn't great for the Brewers if they want to get out from the contract, get back solid young players, or both.
Young, in his first crack at the National League, has fared mildly better than in 2012. At this point the 36-year-old is a complementary offensive player with a poor defensive reputation and a good clubhouse reputation; a contender may pick him up mostly for that reason. Callaspo is a similar player in some ways, but he's signed through next year.
Backups
Cody Ransom (Cubs), Luis Valbuena (Cubs), Kevin Frandsen (Phillies), Placido Polanco (Marlins), Jamey Carroll (Twins)
The Cubs' third base platoon has been highly effective, as their .766 OPS at the position ranks fifth in the NL. Ransom can be under control next year as an arbitration eligible player, while Valbuena can be controlled through 2016. Add in strong part-time work from Frandsen, who is under control through 2015, and the trade market features backup options who have outplayed many regulars in limited samples.
Other Possibilities
Lonnie Chisenhall, Will Middlebrooks, and Mike Moustakas were once among the best third base prospects in baseball, but development has stalled on all of them. The Indians' Chisenhall, called back up on June 18th, has been playing well of late and seems the least likely to be included in a deal. In general, I don't picture the Indians, Red Sox, or Royals giving up on these players this summer.
Biogenesis Effects
Alex Rodriguez is tied to Biogenesis, and could theoretically be slapped with a suspension shortly after making his season debut. Regardless of Biogenesis, though, A-Rod's effectiveness and ability to stay on the field following January hip surgery is a huge question mark. The Yankees would be well-served to explore reinforcements at third base with Kevin Youkilis on the 60-day DL.
You can also check out our trade market posts for catchers, first basemen, second basemen, and shortstops.