On Tuesday night, the Washington Nationals had to play a game against one of the best pitchers in the league without their best offensive player. In fact, simply calling Bryce Harper their best offensive player might be underselling how important Harper is to the lineup. Per Fangraphs, the Nats offense this season has been worth -10.3 Offensive Runs Above Average (or 10.3 Runs Below Average, if you prefer). Bryce Harper has been worth 52.2 Offensive RAA, which means that the remainder of the team has provided -62.5 Offensive RAA.
In fact, the Nats have six players other than Harper who have been on the big league roster at some point this season who have positive Offensive RAA. One is a pitcher (Sammy Solis, 0.2) who isn't in the majors. Another (Emmanuel Burriss, 1.1) is a utility infielder in Syracuse that is no longer on the forty man roster. A third (Denard Span, 9.6) is on the disabled list and doesn't seem close to returning. That leaves starting third baseman Yunel Escobar (4.9), first baseman Clint Robinson (2.1), and the seemingly invisible Danny Espinosa (1.8) as the only three players other than Harper on the roster who have been net positives offensively this season.
Note that not a single one of the players mentioned above have more than 10 Offensive RAA. Heck, three of them aren't on the roster right now, and Espinosa seems to be having a difficult time reminding Matt Williams that he exists. Without Bryce Harper, this offense goes from below average to absolutely dreadful, so they're obviously going to have a hard time scoring runs if Harper does suffer an injury that keeps him out a few games (or longer). With Harper scratched last night, the Nats couldn't even muster a single run.
Of course, the offense isn't the only area where losing Harper would hurt. When the offense is struggling to score runs (95 since the break, 21st in the majors... only expected to decline if Harper isn't in the lineup), run prevention becomes even more important. Pitching may be the most important part of run prevention, but it's not the only factor. When the pitchers induce contact that should result in outs, the defense behind them needs to convert them. There were a couple of key spots where that didn't happen last night for the Nats, and one of them occurred in right field.
At about four seconds of the video above, we'll note somewhat of a circuitous route that Robinson takes on the play. He seems to break straight to his left before breaking in and making a beeline towards the ball. Once he does adjust his route towards the ball, we see him lumbering with the 25 (on the 20/80 scouting scale) speed that he has. He makes a sliding effort to come up with the ball, but comes up short. A typical right fielder with 40+ speed who has more experience getting reads off the bat in the outfield likely makes the catch standing up and prevents those three runs from scoring.
It's not really Robinson's fault for not being fast enough or experienced enough in the outfield. He was playing a position that he simply isn't suited for. He hit well in Tuesday's game, going 2 for 4, and that is why he's on the roster. Heck, it's hard to even blame Matt Williams for having Robinson in right field for last night's game. He just didn't have any better options.
The greatest area of concern here is that defensively Moore and Robinson's best position on the field is one that I know that a lot of you don't believe should exist. They're designated hitters who can play first base and try to be statues who hope that a ball is hit right at them if they're in left field.
With Harper out of the lineup, somebody had to play right field, and there simply isn't anyone other than Harper on the roster (save for Michael Taylor, who was already playing center field) who can do that effectively. It might have made sense to move Jayson Werth back to right field* for the night with Harper out of the lineup, but Robinson has actually played the most innings in the outfield this season of any player available to Williams on the Nats bench. Tyler Moore has played more innings out there in his career, but neither have been very good defensively (Robinson -6 career DRS in the outfield, Moore -12).
*Typically, if you're going to hide someone in a corner outfield spot, you go to left field. Right field usually requires a bit more athleticism and a stronger arm.
The fact that Williams has to turn to Robinson (or Moore) to play right field if Harper can't go is a reflection on the roster construction. After placing Dan Uggla on the disabled list so they could recall Stephen Strasburg, the Nats bench is a man short. They have just four hitters available off the bench right now. One of those spots is occupied by backup catcher Jose Lobaton. The other three spots are all designated for infielders, though the Nats have given Tyler Moore, Clint Robinson, and (well, for a couple of innings) Danny Espinosa time in the outfield this season as well. Sadly, this is a problem that existed before Uggla went on the disabled list with
poor performance back spasms. Uggla probably couldn't even fake left field as well as Moore or Robinson have.
The lack of a true fourth outfielder has been a problem for much of the year. This is partially due to injury. Nate McLouth hasn't even suited up in the minors at all this season as he can't put his shoulder injury behind him. Reed Johnson apparently started taking batting practice three weeks ago, but there's no timetable for his return. Matt den Dekker has been a disappointment this season splitting time between the high minors and the majors. Brian Goodwin has actually been worse in AA this season than he was in AAA last year. Toss in that the Nats best fourth outfielder (Michael Taylor) keeps getting pressed into action because the starters can't stay on the field and we'll see that GM Mike Rizzo had some options to fill that role. Unfortunately, none of them have been able to contribute.
For all that Rizzo has done well over the years, the decision not to pursue another outfielder at the deadline (or at least not pursue one strongly enough to acquire him) is starting to look like a gross miscalculation on his part. Jayson Werth had a good game over the weekend, but he still hasn't been able to find his stroke consistently. There's nobody who can provide a quality defensive backup in the outfield if Werth, Taylor, or Harper are unable to go. The offensive value that Robinson provides doesn't quite offset his defensive liabilities. Moore is a negative on both sides of the ball.
The fact that Rizzo had several contingency plans that have fallen through is all well and good. The decision not to address that those contingency plans fell through a few weeks ago is disappointing. At the very least, it's probably time to get a quality defensive outfielder from the minors up to the big club and on the bench. There's not much sense in continuing to run an eight man bullpen out there.