With full-season All-Star Games wrapping up this week, members of the MiLB.com staff look at some of the most notable performers from the first half and predict who could be poised to take off the rest of the way. After looking at the Class A Advanced and Class A levels last month, we turn our attention here to the Double-A Eastern, Southern and Texas leagues before breaking down Triple-A tomorrow.
Most exciting hitter
Blue Jays 3B Vladimir Guerrero Jr., New Hampshire: Though it feels like we haven't seen him in months, Guerrero -- out since early June with a strained patellar tendon in his left knee -- was unquestionably the most exciting prospect in baseball for the season's first two months. In 53 games at Double-A, the son of the 2018 Hall of Famer batted an absurd .407/.457/.667 with 11 homers, 55 RBIs and nearly as many walks (20) as strikeouts (21) before the injury hit on June 6. It's hard to find a hole in Guerrero's game, and the only ones that exist may be in the field. At the plate, he earned the first 80 grade MLB.com ever bestowed on a prospect's hit tool, and when he returns to the field, it might not be long before the Blue Jays test his advanced approach at Triple-A -- or in Toronto.
Video: New Hampshire's Guerrero hits walk-off blast
Most exciting pitcher
Braves RHP Touki Toussaint, Mississippi: It's been a roller-coaster career for Toussaint, who was taken with the 16th overall selection in the 2014 Draft and looked to be a key piece of the D-backs future. Just one year later, he was shipped to Atlanta along with veteran starter Bronson Arroyo in an Arizona salary dump that may have netted the Braves a future solid starter in a system full of guys who can claim that label. This year, Toussaint appears to finally be putting it all together. Before he was promoted to Triple-A Gwinnett last week, the right-hander led Double-A with 107 strikeouts in 86 innings. His 29.3 percent strikeout rate and 9.9 percent walk rate were the best and second-best, respectively, of his career with full-season affiliates. This half-season was a continuation of Toussaint's finish to 2017 with Mississippi, where he posted a 3.18 ERA in seven starts after putting up a 5.04 mark in 19 outings at Class A Advanced.
Video: Toussaint's 11th strikeout for Mississippi
San Antonio Missions: While New Hampshire could certainly stake claim to this designation with Guerrero, Bo Bichette and others, San Antonio has seen breakout seasons from ranked prospects all year on both sides of the ball. Lefty Logan Allen has led the way on the mound for a league-best pitching staff that includes former first-rounder Cal Quantrill and former third-rounder Jacob Nix. San Diego's No. 1 prospect, Fernando Tatis Jr. adjusted after a slow April to dominate the level in May and June. The shortstop is one of Double-A's youngest regulars at just 19 years old. Behind the plate and at first base, Austin Allen has been among the Texas League's leaders in home runs throughout the season. San Antonio finished just 1 1/2 games off the pace of first-half champion Corpus Christi.
Video: Missions' Tatis Jr. launches second homer of game
Indians RHP Triston McKenzie, Akron: McKenzie didn't make his season debut until June due to soreness in his right forearm developed during Spring Training, but the wait has been worth it so far. Cleveland's top pitching prospect tossed scoreless, one-hit ball over five innings in his June 7 season debut and did the same over 6 1/3 on July 3. As McKenzie continues building up his workload and getting deeper into games, he has a chance to push himself further into the upper echelon of the game's pitching prospects. Just 20 years old, the righty works with a 60-grade fastball and curveball, working his heater into the low-90s regularly and getting whiffs with his hook. Being one of the youngest pitchers at the level is nothing new for McKenzie, who has ascended rapidly since going to Cleveland with the 42nd overall pick as a 17-year-old in 2015.
Video: Akron's McKenzie seals gem with a K
Dodgers 3B Rylan Bannon, Tulsa: A bit under the radar in the Los Angeles system to begin the year, Bannon is establishing himself as a legitimate prospect. While manning the hot corner, he's torn through California League pitching, posting a .559 slugging percentage with 19 homers through 82 games at Class A Advanced Rancho Cucamonga. Taken out of Xavier in the eighth round last year, Bannon's offensive performance after jumping over Class A has shown that his blistering debut season a year ago wasn't a fluke, but he shines especially in the field. The defensive whiz may not have much left to prove as the second half rolls on and could find himself in Tulsa before the calendar hits August.