Speaking from experience, it's not always easy being left-handed. College desks are designed against you, you often get ink marks on the side of your palm, and writing in a spiral notebook can be downright painful. Being a left-handed hitter can be challenging, too. Sure, there are some advantages. You get short right field porches to aim for in places like Yankee Stadium and Camden Yards, but you also have to work around defensive shifts and an entire class of reliever whose sole responsibility it is to get you out. When facing lefty pitchers, left-handed hitters are tracking balls whose starting point is somewhere over their shoulder throwing balls whose natural movement is away from the sweet spot of their bats.
The Yankees don't have very many right-handed batters. Eight of the nine starters in their everyday lineup are either lefties or switch-hitters and nine of their thirteen active position players share one of those labels. Here's how all those guys have performed vs. left-handed pitchers since the start of the 2013 season. The results aren't great.
Mark Teixeira's been historically stronger batting righty, particularly over the past few seasons as shifts have sapped his ability to hit singles to right. Besides he and Carlos Beltran, though, every one of the Yankees' lefties and switch-hitters has fared better against righties career-wise by at least ten points in wRC+. Brian McCann and Chase Headley have done a yeoman-like job hitting left-handers over the past two-plus seasons and Jacoby Ellsbury and Brett Gardner have hovered around league average, but after that things get ugly. Beltran, whose career splits are close to dead even from both sides, has seemingly lost the ability to hit right-handed, even going back to 2013 when he was still a productive hitter for St. Louis. Stephen Drew, Didi Gregorius and Garrett Jones turn the average left-handed pitcher into some sort of Randy Johnson-Clayton Kershaw hybrid.
The Yankees' extreme left-handedness is compounded by the fact that they don't have much bench depth available to play the percentages. Chris Young has been starting vs. lefty pitchers, and he's done well, but having him in the starting lineup takes away a weapon that could be used against a LOOGY later in games. Since the Yankees only have one reserve middle infielder in Gregorio Petit, they can't pinch hit for both Drew and Gregorius in late and close situations, forcing match-ups like the one we saw Wednesday night in the top of the ninth, with the former facing Orioles closer Zach Britton. It's no surprise that one ended with a strikeout. Drew's grand slam was the game-winner Monday, but if Buck Showalter had taken the easy out the Yankees were giving him by bringing in Brian Matusz, we'd probably be talking about a Baltimore sweep.
The Yankees acquired Jones as a hedge against injuries to Beltran, Teixeira and Alex Rodriguez, but while that trio is fully intact, the composition of the roster prevents him from having much of a role. There aren't many pinch hit at-bats to be had for a lefty hitter and there's no reason to swap out Teixeira or A-Rod except for occasional rest days. Right field may eventually evolve into a Young platoon, but Beltran will still see more time, thanks to the $30 million remaining on his contract and the fact that his .254/.331/.446 line batting line vs. righties in 2014 trumped Jones' .250/.314/.435. Jones seems poised to end up as this year's Kelly Johnson - a player the Yankees brought in because his lefty pull swing seemed like it would play well in the Bronx, but who never got enough of an opportunity to show his full mettle. Like Johnson, Jones is used to being in the lineup more often than not, having managed 440 or more plate appearances in each of the past five seasons. It's unclear if he'll ever thrive playing sparsely and the team could probably make better use of his roster spot.
The Yankees have a few minor league right-handed options to consider. Rob Refsnyder's defense is still a major issue, with three errors already in the young Scranton/Wilkes-Barre season after a notoriously choppy swing at second, but Jose Pirela will eventually be healthy and an option as a second middle infielder off the bench. Tyler Austin has a 135 wRC+ through a week's worth of games and like Pirela is already on the 40-man roster. He could conceivably fill the same role as Jones but from the right side of the plate. There probably isn't a move to be made just yet, but their vulnerability against left-handed pitchers is something the Yankees will need to address as the season goes on.