Antoni Flores: The Next Big Red Sox Prospect

Written by: Adam Tulley (@AdamT_Prospects)

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Youth. Polish. Projectability. What else can you ask for in an off-the-radar prospect? Antoni Flores is a very interesting prospect and he is one of my favorite players from the 2017 international class.

In general, the profile of a young, athletic player who already shows polish with plenty of remaining projection is quickly becoming one of my favorite types of prospects due of the rarity of this combination. Some names you already know about who fit that profile? Wander Franco, George Valera and Luis Garcia (the Phillies’ version). Flores has the tools to ascend to a similar level of the above trio, and he’s player I’ll be keeping an eye on as he makes his full season debut in 2019.

Flores was one of many names of note in a LOADED 2017 international class, signing for $1.4 million with the Boston Red Sox. This was a 16-year-old that was an above average defensive shortstop with good hands, range beyond what his speed should allow and great defensive actions. At the time of his signing, Flores already had an extremely projectable and promising frame for professional baseball. As a shortstop, he was initially given a comparison to Alcides Escobar. Thankfully, at his current trajectory, I think he will be much more than that.

Pending inevitable physical development, Flores can be a very exciting player. When he signed, the teenager was a wiry 6’1, weighing-in at only 160 pounds. This is a long limbed body that has a TON of room to grow. In his most recent profiles, it’s obvious he’s already added quite a bit of ‘good’ weight; looking at his body and athleticism, he still has room to grow without hurting his skillset. Below, I have graded out his tools in terms of current value/future ceiling value:


Power Run Arm Field Overall
35/65 30/55 55/55 60/60 60/65


With Flores, I see a guy who has a very high floor as a professional player. As a plus defender at shortstop, he will likely be able to carve out an everyday role even if the offense takes a little longer to develop. As you can see by my future value rankings, I view Flores as an impact player on both sides of the ball. In his prime years, this is a hitter who has a chance to hit in the middle-third of a lineup while also competing for Gold Gloves defensively. I will touch on the future hit/power tools later when I analyze his swing.

The polish is evident in his defensive scouting reports but there is also glimpses of it on offense. When I evaluate prospects in terms of offensive polish, I first look at the plate approach and makeup of a hitter. Flores is a player who knows the strike zone and absolutely dominates it (14.5 BB%, 12.9 K% last season). He hits hitter’s pitches and ignores offerings he’s not equipped to defeat, which led to a .340/.435/.528 slash (173 wRC+) in a mere 62 plate appearances last summer. Simply put, he seems to have a plan every time he steps to the plate. With an all fields approach, it’ll become tougher and tougher to get this guy out as he continues to improve. Below, I have a generated spray chart by Minor Graphs that illustrates the advanced approach that Flores employs.

antoni flores

This visual may not blow you away, but here’s the obvious takeaway: As a 17-year-old playing through two levels of rookie ball (DSL and GCL), Flores was not only able to spray the ball from line to line, but he also made significant impact on the ball to all three quadrants of the field. We can see hits from left field to right field that all landed past the 300-foot mark. Right now, these are flyouts, but as Flores continues to build strength, increases his bat speed and tweaks his swing to add power, these will turn into home runs.

Now let’s jump into the exciting swing analysis of Flores. Below, I have attached a video that the Prospects Live crew captured at instructs this past fall in a matchup against a Rays squad that rostered prospects like Matthew Liberatore and Tanner Dodson.

Here, we see Flores start in a fairly wide, balanced stance with a slight bat waggle that creates rhythm. He employs a moderate leg kick that shifts his weight and hands back into launch position. From there, we see him land balanced and throw his hands directly to the ball, which allows for an efficient barrel path. This is an extremely simple swing that brought Flores unquestioned success in his pro debut.

I mentioned earlier that I would be talking about the increase in hit/power tools and here it is. Although the lower half is good, there is plenty of room for improvement. He does a good job of hitting against a firm front side (see how his knee locks out upon impact with the ball), but at foot strike, he can create much better hip to shoulder separation leading to an increase in bat speed. Hip to shoulder separation is basically the timing at which your hips fire compared to your shoulders. When evaluating the most elite power hitters, you will see the hips fire open while the shoulders stay square. This generates a spring-like loading effect on the upper body and allows the bat to whip through the zone. Great power hitters and pitchers will always have great hip to shoulder separation in common.

As I mentioned, this swing is extremely simple, compact and efficient. Flores is advanced enough as a hitter to make a deliberate effort to ‘sell out’ for more power to continue in his development process without sacrificing too much contact efficiency. Possible adjustments include increasing his stride height, creating more violent movements with his hands and creating a deeper, more powerful load. This is a path I expect to see as Flores moves through the minors. It may hamper his average and on base skills at the start, but the end-game is Flores becoming a hitter capable of posting solid averages and home run totals. We have seen the Red Sox recently develop contact hitters like Mookie Betts into huge power threats; as an organization, they have a track record of developing homegrown hitters like Andrew Benintendi, Rafael Devers Xander Bogaerts, Dustin Pedroia, Jackie Bradley Jr, etc. This leads me to believe Flores will reach his ceiling.

Ceiling Projections: .290/.400/.500 w/ 28 HR, 5 SB

Antoni Flores is a solid bet to always hit for a high average. If he never reaches his power upside, I’d expect batting averages closer to .300 and him scoring a ton of runs while hitting near the top of a lineup.

Remember, this offensive profile comes with sterling defensive value. Flores is an above average defender who has a better chance than most prospects to stick at shortstop throughout the entirety of his professional career. When thinking of a current major leaguer to compare him to, my first thought was Xander Bogaerts. But seeing as Bogaerts is the current Red Sox shortstop, the comp felt a little lazy. This led me to thinking of a more ambitious player comp, and I arrived at a right-handed Corey Seager. Of course, this is the absolute best case scenario (meaning the power develops the way I think it can). In actuality, the Bogaerts comp is probably more realistic.

I expect Flores to become the next ‘former J2 prospect’ name to know. The shortstop was limited to only 15 games last summer due to ‘general soreness’ and then a hamstring injury, but he should begin the 2019 unhindered and fully healthy. I, for one, will be paying very close attention to his power statistics like estimated fly ball distance throughout the 2019 season. If this increase in power comes, I think we’ll see Flores ascend boards this season the same way Wander Franco, Kristian Robinson and George Valera did last summer.

Follow P365 staff writer Adam Tulley on Twitter! @AdamT_Prospects

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