Second-Half Speculation - Prospects to Stash Now

Picking up the right prospect during the second half can make or break a fantasy baseball season. While many of baseball's best prospects, including Vladimir Guerrero Jr., Keston Hiura, Austin Riley, and Brendan McKay have already been called up - there are still plenty of players still in the minor leagues that should get a chance to shine in the big leagues before the year is up.

Here is a look at five players - all who have yet to make their big league debut - who should be stashed in deeper fantasy formats, and should absolutely be on the fantasy radar in 10 and 12-team leagues.

I'll provide a glimpse of when they could get the call, and in what formats they should be owned as soon as they are up.

Bo Bichette (SS, TOR)

Toronto's other elite infield prospect, shortstop Bo Bichette, has been killing it at Triple-A this season. He currently sports a .320/.380/.520 slash line with five home runs and 12 stolen bases in 38 games played. Injuries slowed him to start the campaign, but it's becoming clear that Bichette has little, if any, left to prove in the minors.

With Guerrero cemented at third base for the next few decades, Bichette will need to displace veteran shortstop Freddy Galvis and/or Eric Sogard, the current starters in the middle infield. Toronto also needs to find at-bats for Lourdes Gurriel and Cavan Biggio, both who can play the middle infield.

That's the biggest concern about Bichette at the moment, but if he does find himself getting everyday at-bats, he is a must-own in all fantasy formats.

Toronto will likely look to trade Galvis and Sogard, who are both overperforming, which should free up that spot for him.

Keep a close eye on this situation, and snatch him up as soon as he is called up. If you have an extra spot ahead of time, Bichette is one of the safest stash candidates who has yet to make his big league debut. You won't want to miss out on this budding star.

Jesus Luzardo (SP, OAK)

Prior to the season, most expected left-hander Jesus Luzardo would be with the big league club by the All-Star break. However, injuries have really hampered his 2019 season - although he is healthy now and already beginning to make his case for a promotion.

In three Triple-A starts, Luzardo owns a 3.65 ERA and a ridiculous 14/2 K/BB ratio. That's obviously a tiny sample size, but big strikeout numbers have become the norm for the flame-thrower, and it's expected that will continue when he reaches the big leagues, which could happen by the end of this month.

I do expect some turmoil for Luzardo, who really hasn't thrown a lot of innings since he was drafted, but ultimately his strikeout stuff and the fact that he plays his home games in a big park should allow him to be a top-50 starting pitcher down the stretch, provided he stays healthy and doesn't face any kind of injury shut down.

Once he is called up, he should be added in all formats. He's already owned in 18% of Yahoo! leagues, so it might not be a bad idea to stash him now so you don't miss out.

Isan Diaz (2B/SS, MIA)

Diaz could have a very strong impact on fantasy baseball teams if he gets an everyday role in Miami this year, but the presence of Starlin Castro and his big contract make that vision harder to see. Castro will certainly be gone after this season, which frees Diaz up to start at second base and - hopefully for Miami fans - become the franchise player at that spot.

Diaz is crushing the ball so far in 2019, boasting a .289/.386/.560 slash with 20(!) home runs, 69 runs scored and four stolen bases in 83 games played. He's always possessed raw power - particularly for a middle infielder - and the juiced ball make him a potential 25-30 home run candidate in the show.

Diaz is one to keep an eye on this season, although he is really only going to be worth picking up if he is playing every day, which may take a trade or an injury to Castro for that to become a reality.

Jorge Mateo (SS, OAK)

Mateo has always been a prospect with blazing speed, but inconsistency at the plate slowed his development and had him well off most prospect radars after a disappointing 2018 season where he slashed just .230/.280/.353 with three home runs in 510 plate appearances at Triple-A, his first full season in the A's system.

However, even in an ugly year at the plate, Mateo still managed to swipe 25 bases, continuing a trend of elite base stealing that goes all the way back to his first minor league season, when he swiped 49 bases in just 64 games in Rookie ball in 2013.

Mateo's speed is still there, but now the bat is back too - and he's knocking down the door for a big league promotion. In 82 games at Triple-A, Mateo is slashing a wicked .308/.342/.533 with 18 stolen bases and a career-high 13 home runs. Sure the power is inflated by Triple-A's use of the juiced baseballs, and his plate discipline numbers are somewhat concerning, but there's reason to believe that Mateo could hit 8-10 home runs and steal 15 bases if he were called up to the A's right away.

With Jurickson Profar and Franklin Barreto struggling, Mateo could end up in a full-time role in Oakland sooner rather than later.

I'm adding him in very deep leagues right away, and would want to snatch him up in 14+ team leagues as soon as he is recalled. If he gets an everyday role, he would be worth a look in 12-teamers for owners who are desperate for steals.

Jake Fraley (OF, SEA)

Fraley was a relatively unheralded prospect when he changed hands last offseason, coming from the Rays to the Mariners in the deal that sent Mike Zunino to Tampa. Although he had posted some solid numbers in the low minors with the Rays, no one expected the kind of break out he has shown with the Mariners so far this season.

He began the year at Double-A, getting his first taste of that level. He absolutely feasted, slashing .313/.386/.539 with 40 runs scored, 11 home runs, 47 RBI and 16 stolen bases in just 61 games played.

His Triple-A numbers are almost just as good, with a .305/.354/.661 slash line, four home runs, three stolen bases and 19 RBI in just 14 games played.

Fraley only has 14 games at Triple-A, so a call-up probably isn't imminent, but the Mariners may have lost Mitch Haniger for the entire season and could make trades involving Dee Gordon, Domingo Santana and/or Kyle Seager, which will free up at-bats that the team will need to give to someone.

If Fraley continues to rake down in Tacoma, a September call-up seems likely - and he could be up even sooner if the team moves some players in late-July.

A top-of-the-order table setter with a nice combination of power and speed, Fraley would be worth a look in 14+ team leagues when he is called up, and could make his way onto the 12-team radar if he is playing every day.

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