Mariners add needed depth to roster

After his latest spree of acquisitions, I noticed something about the position players Jerry Dipoto has been accumulating. Maybe you’ve noticed it too. Carlos Ruiz, Danny Valencia, Richie Shaffer, and Taylor Motter all hit from the right side of the plate. When half of the regular starting lineup is left-handed, the need for right-handed depth is critical for the Mariners. Dipoto recognized this weakness on the roster and took three steps to correct it.

In 2016, the Mariners were actually an above average team when facing a left-handed pitcher, boasting a 106 wRC+ as a team. But much of that performance was buoyed by Nelson Cruz, noted lefty masher. If you remove his stats from the team totals against southpaws, their wRC+ drops to 99. Dae-ho Lee and Franklin Gutierrez were excellent against lefties too, but because of the makeup of the roster, they became starters when facing a left-handed starting pitcher. That meant Scott Servais had very few right-handed options off the bench if he needed a late inning pinch hitter or if a starter was dealing with a minor injury.

Over the last two years, the Mariners’ right-handed depth has been just barely over replacement level and has been more than 20% below league average at the plate. (The table below excludes Dae-Ho Lee and Franklin Gutierrez from the 2016 total because they were platooned so heavily they could be considered nominal starters.)

When players like Luis Sardinas, Daniel Robertson, and Stefen Romero are providing this kind of depth, it’s no surprise the Mariner have had such poor performances against left-handed pitching. What’s also telling is the number of plate appearances the Mariners received from their right-handed depth in 2016—more than 700 fewer than in 2015. Most of these missing plate appearances went to Lee and Gutierrez who were already playing regularly against lefties. Including their numbers raises the collective performance of the group but the rigid playing time limitations limited the flexibility of the roster.

With the additions of Ruiz, Shaffer, and Motter, the Mariners have added three players who could capably fill in at a number of positions. Besides the value their flexibility provides, these three players project to hit better than their counterparts from the last two years. Using the Steamer projections from FanGraphs, here’s the cumulative line for the seven right-handed depth players on the 40-man roster.

The WAR total is boosted by Ruiz’s positional adjustment and the improvement might seem slim, but every little edge counts. Both Shaffer and Motter are young and possess multiple minor league options. They may move the needle just slightly, but considering the dearth of right-handed depth this team has seen the past few years, they’re a welcome sight.

Dipoto isn’t nearly done shaping the Mariners’ roster. There are still a number of holes that need to be filled. But early in this offseason he identified a need to field a more balanced lineup. He’s filled it with capable players while increasing the overall flexibility of the roster. Jack Zdurienck was completely unsuccessful when making these types of moves and that lack of depth sunk the Mariners time and time again. Acquiring depth pieces may not make for exciting headlines and they probably won’t push the Mariners into pole position in the AL West, but they do raise the floor of the roster mitigating the attrition suffered during a 162-game schedule.