What happened to Andrew Benintendi? And can he rebound from it?

In a small sample size this year (14 games), Andrew Benintendi posted troubling numbers.Jim Davis/Globe Staff

What has happened to Andrew Benintendi?

It’s not that long ago the 2015 Red Sox first-rounder seemed like a certain bet for stardom. Baseball America ranked him the No. 1 prospect in the game entering 2017, with scouts falling out of their chairs over his skill set.

At that time, one American League evaluator envisioned him as a center fielder who would win multiple batting titles, an eight- to 10-time All-Star whom he ranked alongside Mike Trout, Bryce Harper, and Mookie Betts as one of the best minor leaguers he’d seen.

“He’s a once-in-a-decade hitter,” said the scout.

A National League evaluator gave Benintendi an “80” grade as a hitter on the 20-80 scouting scale, and suggested he would regularly deliver 70-80 extra-base hits a year. Such projections didn’t seem out of place for a player who’d won every college award imaginable as a sophomore at Arkansas and was not fazed by blitzing to the big leagues in just over a year.

So what does the 2020 season mean? What does it say that, in a year when he was limited to just 14 games before a season-ending rib injury, Benintendi hit .103 (second-worst among the 414 players who had at least 50 plate appearances), slugged .128 (easily the worst in the majors), struck out in 32.7 percent of plate appearances (the 89th percentile), and when he did put the ball in play, did little except for pulling ground balls?

Unquestionably, Benintendi has the ability to be a far better player than he was in the two-week glimpse of 2020 preceding his rib injury. After all, numerous players — many elite — struggled badly to adjust after the spring shutdown and abbreviated buildup to a season.

Certain elements continue to work in Benintendi’s favor. He turned 26 in the middle of last season, and he still isn’t that far removed from looking like a player coming into his own in the first half of 2018.

Nonetheless, there are yellow and red flags that raise questions about just what remains possible.

Heat index

When he arrived in the big leagues, Benintendi had such a sweet, compact swing that it seemed hard to imagine him getting beaten by fastballs. Yet the effortlessness he displayed in catching up to velocity has eroded over time.

In 2017, according to BaseballSavant.com, Benintendi hit 15 homers and slugged .477 against fastballs while just 15.1 percent of his swings against them resulted in misses. His slugging percentage and homers have gone down every subsequent year against fastballs, while his swing-and-miss rate has steadily climbed.

Also of note, he’s using the opposite field far less, preventing him from taking advantage of Fenway Park. So, in addition to making less contact against fastballs, an increasing amount of his solid contact has resulted in long outs.

A red flag on speed

There is an easily overlooked yet consistent source of worrisome decline in Benintendi’s game: His speed. Or rather, his lack thereof.

Statcast measures “sprint speed,” the feet per second covered by a player in his fastest one-second window. Two kinds of plays contribute to the measurement: advances of two bases or more on non-homers, excluding going from second to home on extra-base hits; and going from home to first on weak grounders.

The big league average sprint speed is about 27.0 feet per second. When Benintendi reached the big leagues in 2016, Statcast measured his average sprint speed at 28.6 feet per second — a mark that ranked as elite, the 89th percentile in the majors. His speed has declined in each subsequent year, down to a below-average mark of 26.6 in 2020 (again, small sample size warnings are necessary).

That rapid dropoff borders on alarming, not only limiting his impact on the bases (it’s worth recalling that he was 41 for 49 in stolen base attempts, an 84 percent success rate, in 2017-18) but also raising concerns about his defense. That sort of speed borders on disqualification for center field; of the 54 big leaguers who had at least 10 opportunities in center, just six had below-average sprint speeds. It also contributes to the view of multiple evaluators that Benintendi’s defense in left has deteriorated.

Sprint speed tends to remain stable for players in their 20s, and small year-over-year improvements do happen. But even at 26, it’s unlikely that Benintendi will regain the speed he featured at the start of his career.

“A huge concern,” one NL evaluator said.

“His value takes a hit with me because I do not see him as a center fielder, nor a particularly good left fielder,” said an AL scout.

A puzzling value proposition

There has been speculation about Benintendi as a trade candidate, with some belief in the industry that he could benefit from a change of scenery. But does it make any sense for the Red Sox to consider dealing him?

Benintendi will earn $6.4 million in 2021 — the second season of a two-year, $10 million deal he signed in January. Beyond that, he has one more year of team control before he’s eligible for free agency following the 2022 campaign.

Under those terms, his value seemed like it would have been considerable coming off a slightly down 2019 season that nonetheless showed several solid elements, including career-best exit velocity and plenty of solid contact. But now, after a catastrophic if brief performance in 2020, and with the market likely suffering this winter because of the impact of the COVID-19 pandemic, Benintendi’s trade value relative to free agent alternatives likely would suffer.

“I think his trade value is pretty limited at this point,” said one evaluator. “[A] willingness [by the Red Sox] to sell at this low point of value would suggest that the people who know him the best don’t see a dead cat bounce coming, which would give me a lot of pause, because every metric is pointing down.

“He’s young enough that it seems unlikely that he should be toast as a player, but I wouldn’t want to bet heavily that he’s going to turn into a good player again.

“Is he better than Robbie Grossman these days? I would say probably not. And Robbie Grossman [is] not getting big bucks this winter.”

At the same time, no one has forgotten what Benintendi looked like in 2018, when he was an emerging star in the first half of the season and a run-scoring machine in the postseason.

“I still feel the 2017 and 2018 Benintendi are what you will get this 2021 season,” said one NL evaluator. “I think this past season was a fluke.”

If it was, in fact, a fluke, the Sox wouldn’t want to sell him at a low-value point. Given his potential upside and the likely modest return Benintendi would bring, the risk of dealing him likely exceeds the payoff.

The most sensible path for the Red Sox is to hope to bring Benintendi back to the all-fields, slashing doubles hitter who seemed on the cusp of stardom two years ago. Whether such a turnaround remains possible is one of the most significant questions confronting the organization this winter.