Top MLB Prospect Call-Up Radar Report, Week 16

The upcoming trade deadline may be hijacking most of the headlines, but many MLB teams already have significant second-half upgrades in their farm systems. This batch of B/R's MLB Prospect Call-up Radar will focus on which players are likely to make an impact over the season's final months. 

With the season into the second half, we've had to adjust the radar system. Here's the system we'll use to  predict the following prospects' anticipated debuts:

• Red: 2016 call-up
• Orange: September call-up
• Yellow: August call-up
• Green: Call-up is imminent

Over the next few slides, we'll decide when you can expect to see names like Jon Gray, Mark Appel, Michael Conforto and Aaron Judge appear in the big leagues. Make sure to leave comments in the section below, letting us know if you agree or disagree with each player's expected promotion. 

Aaron Judge, New York Yankees

Mark J. Rebilas-USA TODAY Sports

Aaron Judge is putting it all together this season and could be in the big leagues at the start of 2016.

2015 Stats (AA/AAA): .282/.352/.485, 14 HR, 55 RBI, 45 R

When ranking prospects in terms of power, New York Yankees slugger Aaron Judge should always be near the top of the list.

Judge's pop has been on full display this season. Between Double-A and Triple-A, the 23-year-old has 14 homers and 55 RBI. That's coming off the heels of a 21-homer season in 2014. 

The 6'7", 275-pounder does have some swing-and-miss in his game—he's fanned over 20 percent of the time at any stop where he's played in over 60 games. But Judge has always been able to offset his tendency to swing and miss with a watchful eye at the plate. 

Those numbers are definitely impressive, but Judge is still unlikely to reach the Bronx in 2015.

"Ask Keith Law, and he'll say that both he and scouts agree that Judge is going to close the gaps that remain in his plate coverage," said B/R's own Zachary D. Rymer. "But it's a good bet that will take time and that the Yankees won't promote him until it happens. That could be this September, but next year is a safer bet."

Radar: Red

Judge should finish the year out in Triple-A, fine-tuning his game and continuing to improve his plate discipline. 

But come 2016, Judge has a very good shot at making the big league club out of spring training. 

Nomar Mazara, Texas Rangers

John Minchillo/Associated Press

Nomar Mazara is one of the fast-rising outfielders in the minor leagues.

2015 Stats (AA): .285/.358/.445, 11 HR, 47 RBI, 41 R

Texas Rangers outfielder Nomar Mazara is one of the fastest-rising prospects in all of baseball. The 20-year-old has moved into Baseball America's Top 50 Rankings after a stellar first half in Double-A. 

Competing against pitchers much older than him, Mazara has impressed against Double-A arms. He's hitting .285 with 11 homers and 47 RBI in 87 games. Hazara has fanned in over 21 percent of his at-bats, but he's shown improving plate discipline by walking at a healthy rate. 

Mazara's power continues to develop as his body matures. At just 20, it's scary to think about his future homer potential.

“He has his plan, and he’s not going to go away from it when he goes to the box,” fellow prospect Nick Williams told Jeff Wilson of the Fort Worth Star-Telegram. “Not necessarily that he has to swing at that one pitch or that one fastball, but he picks an area where he wants the ball, and if it’s there you never know what he might do with it. He might hit the ball out of the stadium.”

Radar: Orange

With over 100 games under his belt at Double-A, Mazara isn't too far away from a promotion to Triple-A. 

There's no sense in calling him up too early, but continued success at the plate should warrant at least a September cup of coffee with the Rangers. 

Mark Appel, Houston Astros

Mark J. Rebilas-USA TODAY Sports

Mark Appel should get an opportunity to help the Houston Astros sometime in 2015.

2015 Stats (AA/AAA): 6-3, 4.79 ERA, 82.2 IP, 63 K, 31 BB

It's not unusual for top pitching prospects to make their mark in the majors in a modified role. Houston Astros right-hander Mark Appel has the electric stuff to become that next bullpen ace.

On the surface, Appel's numbers are pretty bad. He's posted a 4.79 ERA in 17 starts between Double-A and Triple-A this season. The right-hander's strikeouts are down and his walks are up. If Appel can't handle minor league hitters, how in the world will he be able to hang in the big leagues?

Although Appel is still learning the intricacies of being a starter, his stuff plays right now in the bullpen.

Shorter stints would allow him to unleash his fantastic fastball, which would consistently sit in the upper-90s if he didn't have to worry about going deep into games. He could then couple his heater with a wipeout slider, giving him the swing-and-miss pitches needed to succeed out of the pen.  

Radar: Yellow

Sellers will have their eyes on Appel leading up to the trade deadline, and it's entirely possible that he's moved before then. 

If he remains in the organization after July 31, the Astros will overturn every rock in their quest to return to the postseason. Despite his struggles, Appel will get his chance to prove if he can be a weapon down the stretch. 

Alen Hanson, Pittsburgh Pirates

Gene J. Puskar/Associated Press

With injuries to Jordy Mercer and Josh Harrison, the door is open for an Alen Hanson promotion.

2015 Stats (AAA:): .286/.331/.416, 5 HR, 38 RBI, 48 R, 26 SB

Alen Hanson has proven that he's ready for a new challenge, and injuries to Jordy Mercer and Josh Harrison could be the events that push the Pittsburgh Pirates into promoting the young infielder. 

Hanson has been incredibly steady over the last two seasons. In 2014, he hit .280 with 11 homers and 25 steals in Double-A. So far in Triple-A this season, Hanson has shown a similar blend of offensive ability. 

The 22-year-old probably profiles as a second baseman at the next level, but he has the speed, athleticism and instincts to play all over the diamond. Decimated by injuries, the Pirates have begun getting Hanson some consistent time at third base. 

“He is NOT moving to third base,” general manager Neal Huntington told Stephen J. Nesbitt of the Pittsburgh Post-Gazette. “He IS gaining experience at an additional position to potentially help make a ML team and to help a ML team win games. This was a part of the plan for Alen but our recent injuries has shifted to timeframe forward.”

Radar: Yellow

With injury concerns with both Harrison and Mercer, the Pirates will be in the market for a dependable infielder before the deadline. 

But that reliable player may already be in the organization in Hanson. He's proven just about all he can in the minor leagues, so expect Pittsburgh to see what he can do sometime in the near future. 

Michael Conforto, New York Mets

Brad Barr-USA TODAY Sports

The Mets need offense and could look to Michael Conforto for a spark.

2015 Stats (A+/AA): .301/.377/.489, 12 HR, 54 RBI, 46 R

Michael Conforto has played just 44 games at the Double-A level in his minor league career, but a New York Mets team desperate for offense is seriously contemplating giving him an opportunity to make a splash in 2015. 

According to Kristie Ackert of the New York Daily News, the Mets have "had serious discussions within the last few days about calling the Double-A outfielder up as soon as this week, possibly Thursday when the Mets open a series against the Dodgers at Citi Field."

Whether Conforto is ready for big league pitching can be debated, but New York's need for an offensive boost cannot. The Mets rank 29th in MLB in runs scored this season and have holes up and down the lineup. 

As far as potential upgrades, Conforto has thrown his name into the ring by mashing since being selected in the first round of the 2014 draft. The outfielder hit .331 in 42 games at Low-A last season and has impressed at both High-A and Double-A in 2015. 

Radar: Green

Although promotion seemed improbable earlier this season, the Mets seem willing to try anything to improve their anemic offense.

Like all young hitters, Conforto will face his share of growing pains. But his advanced approach at the plate indicates he can offer some sort of production down the stretch. 

Jon Gray, Colorado Rockies

Darron Cummings/Associated Press

Jon Gray has shown significant improvement since the beginning of the season and should be called up to the big leagues any day now.

2015 Stats (AAA): 5-6, 4.57 ERA, 104.1 IP, 97 K, 37 BB

Before the regular season, the Colorado Rockies decided to send top pitching prospect Jon Gray back to Triple-A for some additional seasoning.

But Gray responded to that decision by pitching some of the worst baseball of his life. The right-hander began 2015 by giving up 21 runs in his first four outings. After narrowly missing out on a rotation spot out of spring training, Gray had his work cut out for him if he was to finally taste the big leagues. 

Since that awful start, Gray has turned his season completely around. Since his fourth start, the 23-year-old has allowed three earned runs or less in 12 of his next 14 outings. He's significantly lowered his ERA and has flashed the strikeout stuff that's made him so highly regarded. 

Radar: Green

Gray has logged over 220 innings between Double-A and Triple-A over the last two seasons and has improved significantly since a disastrous start.  

With little left to prove in the minors, Gray has earned his shot. The Rockies would be wise to let their top prospect get his feet wet in 2015 so he's ready to go at the beginning of next season.

Stats courtesy of FanGraphs and accurate as of 7/23.