In my Carlos Beltran free agent profile post last week, I pointed out that one of his greatest strengths was being a switch hitter who hit both right and left-handed pitching well. What I neglected to mention in the later posts about Brian McCann and Shin-Soo Choo was that they, as strictly left-handed hitters, don't offer that same flexibility.
McCann 2013 vs. LHP- .231/.279/.337, .296 wOBA in 111 PA
McCann career vs. LHP- .259/.319/.424, .326 wOBA in 1,300 PA
Choo 2013 vs. LHP- .215/.347/.265, .292 wOBA in 221 PA
Choo career vs. LHP- .243/.340/.341, .310 wOBA in 1,128 PA
McCann was better against lefties in years past, although there's always been a pronounced split when compared to righties. But he was below-average in 2013 and has been trending downwards recently. The dramatic split in BB rate against lefties (3.6%) and righties (12.0%) is particularly concerning. Choo has been pretty crappy against southpaws since he came into the league. If it weren't for his ability to maintain a high BB rate against them he would offer almost no value against left-handed pitching whatsoever. He could still serve a purpose as a table setter at the top of a lineup against lefties, but that's about it.
Not saying either of these guys should be off the table because of their crummy platoon splits. Just saying these are the type of things that deserve a closer look when you're talking about signing players in their 30s.