MESA, Ariz. – From the moment Xavier Isaac set foot in Arizona, his confidence was sky high. It took all of one batting practice session for MLB’s No. 36 prospect to know that with a left-handed swing geared to send the ball soaring over the fence, he’d have a blast hitting in the Fall League.

While the 20-year-old got his first hit out of the way in his opening salvo Monday, he made his first significant impact during Mesa’s 6-4 loss to Salt River on Thursday afternoon at Sloan Park -- and it was a loud one.

There are just seven ranked prospects across baseball who have earned a 65 or higher power grade from MLB Pipeline, and Isaac belongs to that group. All are also ranked in the Top 100 Prospects list, with Isaac and Kansas City’s Jac Caglianone the only ones currently taking cuts in the AFL. In many regards that makes the Rays first baseman one of the most prolific sluggers on the circuit.

When the Rays selected Isaac during the first round of the 2022 Draft out of the North Carolina high school ranks, his power potential was evident. At 6-foot-3 and 240 pounds, he has unleashed some prodigious wallops during his first two full Minor League seasons. But of those 37 homers across three levels, just one came against a southpaw.

Which made Isaac’s first Fall League homer all the more unique as he took a left-hander -- Dustin Saenz (Nationals) -- way out to right-center field. The first two pitches of the second at-bat of the game for the Rays’ No. 2 prospect were called strikes, but when the third offering was a near replica of the first, he took a hearty cut.

“First pitch, I got a pitch up and I didn’t swing and it kind of irritated me,” Isaac said. “So I was like, ‘If he goes up again, I have to kill it.’ So he went down for the second-pitch strike. I was like, ‘All right, well, cool. I think he's gonna throw it here, so just be ready.’ He ended up throwing it [up] and I just made sure I didn't miss it.”

As Isaac strode down the third-base line toward the plate, he broke out the “rock the baby to sleep” celebration against a pitcher who had the age advantage in 99.1 percent of his plate appearances. Isaac has put that particular move on display throughout 2024, a season in which he homered 18 times across two levels.

While there are countless powerful swinging left-handers for young sluggers to model their approach after, Isaac has an affinity for a former two-time Fall Leaguer -- Bryce Harper. Isaac was in elementary school when the two-time MVP was getting his feet wet in pro ball on the premier prospect circuit for Scottsdale in 2010 and ‘11, but now he’s on the same stage.

“I can't wait to meet him,” Isaac said of Harper. “Just his mentality to the game, how he brings it, his leadership. … I think people think that's cocky, but it's just that he's confident in himself and he knows every time he goes up there, he's probably gonna hit a homer. I love watching him swing the bat.”

Isaac helps to form a formidable cadre of Rays prospects on hand in the Fall League. Having taken over as the top-ranked farm system in baseball during MLB Pipeline's 2024 in-season ranking, the organization has been aggressive in challenging its top talent with the fall assignment, having tabbed MLB’s No. 4 overall prospect and 2024 MiLB Defensive Player of the Year Carson Williams last year.

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Isaac played alongside Williams for a late-season spell with Double-A Montgomery, en route to a Southern League Championship Series berth. While the overall numbers (.694 OPS, 40.6 K rate) didn’t jump off the page for the 20-year-old in his first stint at the higher level, he closed out the season with hits in 11 of his final 15 games and posted a .368 on-base percentage in September.

When Tampa Bay went through with a name change to become just the Rays prior to the 2008 season, Isaac was 4 years old. But proud of its roots, the organization recently reintroduced the “Devil Rays” throwback uniforms as an alternate, leading Isaac and other prospects to convince involved parties that it should be worn during the Fall League.

“This is the best jersey,” Isaac said. “Everything looks good with it.”

Especially home runs from top prospects.