A bulked-up Victor Robles had a down year. He’ll look to fine-tune his game in winter ball.

He had been a Gold Glove finalist who finished sixth in Rookie of the Year voting, a sign that he may ascend up the order and meet the hype of his arrival. But Robles struggled with one noticeable difference: Manager Dave Martinez noted that he gained 15 pounds of muscle while working out through the coronavirus pandemic. Martinez saw that impact Robles’s speed and flexibility, accounting for the poor results on defense. His offense, however, is a harder puzzle to figure out. Numbers and observation point to Robles starting poorly and, in turn, chasing results instead of staying patient, something the Nationals have stressed with him since he debuted in 2017.

The recipe brought little good.

“Sometimes the best thing you can do is see pitches,” Martinez said of Robles in September, adding then that he’s “not awful right now” and still has much room to grow. “Try to get the ball in the strike zone. Know which balls you can hit hard and wait for that one pitch. I’ve been there before. You start trying to swing your way out of it, sometimes you start chasing way out of the zone and obviously he’s done that quite a bit.”

The most concerning evidence is that Robles swung at the first pitch in 41.3 percent of his plate appearances, well above the league average. That can be a solid strategy for some hitters. But it’s a less encouraging sign when the final numbers are a .293 on-base percentage, 53 strikeouts to nine walks, and just 37 hits in 52 games.

And though Martinez mentioned Robles chasing pitches, the numbers don’t reflect any shift in approach. His rate of swinging at pitches outside the strike zone was very similar to 2019, a much better offensive season for him. He saw a nearly identical distribution of fastballs and breaking pitches. His swing percentage — accounting for how often a batter swings — hardly changed, either.

Yet his contact was down and production sagged. That hints at poor timing and worse pitch recognition. Or, as Martinez often suggested, Robles also had trouble adjusting to his new physique. The manager was quick to say that Robles was not out of shape. He frequents the gym in normal times, always ending game nights with a lift that leaves him sweating before interviews. But he was slower, slipped on defense and generated very limited power in the box. Each development, backed by advanced statistics, made it hard to see what all the added muscle is for.

In 2019, Robles’s average sprint speed — measured by Statcast in feet per seconds — was 29.3 with 62 “bolts.” Bolts account for any time a runner is moving above 30 feet per second, and 62 was the fourth-most in baseball. Now contrast these numbers to 2020, when Robles’s average speed was 28 and he finished a shortened year with just four bolts.

He lost a lot of his quickness. Martinez explained on multiple occasions that his first step was slower in the outfield, leading to a handful of balls to drop in shallow center. For another sharp regression, Robles led all outfielders with 25 defensive runs saved in 2019. A year later, with the metrics warped by the condensed schedule, Robles ranked 48th with -4 runs saved and only preserved the perception of his strong defense with a handful of eye-popping plays. Then there was a concerning trend at the plate.

In all, Robles put 118 balls in play in 2020. Only 27 of them traveled 95 mph or faster, putting him in just the second percentile of hard-hit percentage. His average exit velocity was a quiet 82.2 mph, good for the bottom 1 percent of MLB. It’s tough to hit well when hitting that soft.

“I know he’s trying really hard,” Martinez observed in September. “Too hard sometimes.”

And with the added muscle, Martinez was willing to see if Robles could adjust: “We don’t talk to him about necessarily the weight gain. We talk to him about his flexibility, his speed, agility, his first step, I mean, stuff like that. If he feels like he can carry the weight, then we really want him to really hone in on his flexibility and his first-step quickness.”

As this past year wound down, Martinez seemed torn on Robles playing winter ball. On one hand, the manager recognized the benefit of Robles seeing more pitches and getting more reps in the outfield. On the other, Martinez felt that Robles, though young and spry, may benefit from another break. With the promise of a shuffled lineup next spring, the Nationals could really use stark improvements from Robles’s spot in the order, whether it’s seventh, eight or near the top.

Offseason at-bats with Águilas Cibaeñas now bring the chance to fine-tune out of the spotlight. Robles’s next steps will ride on how that goes.