Rays hitting coach Chad Mottola had seen enough of Randy Arozarena during Spring Training to know that the young outfielder had elite bat speed. But there was one specific moment in which Mottola knew the Rays had a rising star on their hands.

That moment came on Sept. 7 against the Nationals. Arozarena came into the game as a defensive replacement in the seventh inning, but it was his bat that did the talking in the eighth, as he launched a solo home run off reliever Tanner Rainey. As Arozarena walked back into the dugout, Tampa Bay infielder Joey Wendle stopped him, making sure he knew that was one of the most impressive swings he had seen in his career.

The fact that Arozarena hit a home run wasn’t the impressive part. It’s how he did it. Rainey is known for having an elite fastball, one that ranks in the 92nd percentile in velocity, with above-average spin. That, combined with his slider, puts him in the 99th percentile in whiff rate and strikeout rate. That didn’t seem to matter to Arozarena.

After Arozarena fouled off a 96.8 mph fastball at the top of the zone, Rainey went back to the heater in a 1-1 count, painting a 97.3 mph fastball on the inside corner. With the count at 1-2, Rainey decided to go back to the heater in the same zone that Arozarena fouled off the first one. This time, Arozarena was ready, smacking the fastball over the left-field fence with a 103.8 exit velocity off the bat, per Statcast.

“[Rainey] was blowing fastballs past everyone, but then he caught up to a neck-high heater that nobody else could touch,” Mottola recalled. “That’s when you knew it was different. We could tell he had special bat speed, but that’s when you saw that it was at a whole different level.”

Here’s a breakdown of how Arozarena’s regular season, and in some ways, that single at-bat, foreshadowed his postseason success.

Crushing fastballs
Arozarena's home run off Rainey came on a 98.1 mph pitch that was 3.11 feet above the ground. There were plenty of homers this season on pitches either faster than that or higher than that, but Arozarena’s was one of only six on a pitch at least that fast and that high in the zone, further evidence that he can catch up to many fastballs.

Five of Arozarena’s seven home runs this postseason have come on fastballs, and that should come as little surprise considering what he did in the regular season. Arozarena hit seven homers in 23 regular-season games, all on fastballs, while hitting .316 and slugging .895 in at-bats that ended on heaters.

The contact Arozarena made backs that up. He had a .306 expected batting average and .684 expected slugging percentage in at-bats ending on fastballs. Those metrics, which are based on quality of contact, plus strikeouts, indicate that Arozarena’s fastball contact was quite good -- and he wasn’t merely getting lucky when hitting them.

That’s continued in the postseason, with five homers, a .526 batting average and a 1.421 slugging percentage in at-bats ending on fastballs. And yet again, the quality of contact backs up the results we are seeing: a .454 xBA and 1.064 xSLG on fastballs for Arozarena in the postseason. While both numbers are lower than the actual ones, they aren’t so far away as to imply he shouldn’t be having the results he’s seen.

Hard contact and batted-ball profile
Arozarena’s home run off Rainey had a 103.8 mph exit velocity -- not quite in the 115-plus mph Giancarlo Stanton echelon, but nothing to scoff at, either. The sample size in the regular season was pretty small, but there were already indications that Arozarena could hit the ball quite hard. He had a 90.3 mph average exit velocity and 44.2 percent hard-hit rate, both of which were well above the Major League averages of 88.0 mph and 37.6 percent, respectively.

In other words: Arozarena hit the ball hard. In a limited sample, he had a 14.0 percent barrel rate, while the MLB average is below 8 percent. The common theme here thus far is that the contact he made was quite frequently optimal.

In related news, if we look at Arozarena’s batted-ball profile, the three most similar hitters to him in 2020 were Nelson Cruz, Wil Myers and José Abreu, all of whom had strong offensive years and crushed the ball.

In the playoffs, that hard-hit prowess has been even more on display. Arozarena has 26 hard-hit batted balls this postseason, the most of any player, and he's hit 65 percent of his batted balls with at least a 95-plus mph exit velocity. His eight barrels are also tied for the most, with the Dodgers' Corey Seager.

Adjustments: Non-fastballs
We know that Arozarena can catch up to any heater, but what happens when pitchers make an adjustment and start throwing more breaking pitches? Well, they already have, and that’s what makes this run even more impressive.

Over the course of the regular season, Arozarena saw 53.7 percent fastballs, 30.4 percent breaking balls and 15.8 percent offspeed pitches. But in the postseason, pitchers have adjusted -- see fastball-hitting prowess above -- and have changed that mix up quite a bit. He’s seeing 41.5 percent fastballs, with breaking pitches actually coming in more frequently -- 48.1 percent of the time. The other 10.4 percent has been offspeed pitches.

Arozarena has adjusted right along with the pitchers, and he's gotten hits, particularly on breaking pitches, this postseason.

Arozarena went 2-for-13 with no home runs on breaking pitches during the regular season. In the postseason? He’s 10-for-29 with two home runs.

“Even when he makes an out, you can tell that there was a plan,” Mottola said. “He just spoils some pitches trying to get to the mistake, and some of them haven’t even been mistakes. That’s the kind of thing that makes you feel like there’s some longevity to this and he’s a player we’re lucky to have.”