Fantasy owners were rewarded this week with the arrival of White Sox No. 2 prospect Michael Kopech, a player who has been a fixture in MLB Pipeline's fantasy rankings throughout the season.
Making his Major League debut against the Twins on Tuesday, Kopech scattered three hits over two scoreless innings and struck out four batters before a rain delay forced him from the game. The 22-year-old averaged 96.8 mph on the 40 fastballs he threw in the outing as well as a spin rate of 2,615 rpm, putting him in elite company in both departments.
Barring any more rain-shortened outings, Kopech has the potential to serve as a fantasy asset down the stretch with his knack for missing bats and command that had improved considerably in the weeks ahead of his callup.

With Kopech in the Majors, now is a good time for an updated listing of MLB Pipeline's top 10 fantasy prospects currently in the Minors. As always, they're ranked on expected 2018 fantasy production in the big leagues, while our Top 100 Prospects list reflects long-term value in all phases of the game.
:: Complete prospect coverage ::
1. Eloy Jimenez, OF, White Sox (Previous rank: 2)
Jimenez believes he's ready to contribute in the big leagues this season, and his .360/.402/.611 line, 11 home runs and 29 RBIs in 46 games at Triple-A Charlotte suggests the same. He has nothing left to prove in the Minor Leagues, though the White Sox may delay his callup until next season due to service-time concerns.
2. Vladimir Guerrero Jr., 3B, Blue Jays (previous rank: 3)
There are no signs to suggest that the Blue Jays will promote the 19-year-old phenom when Triple-A Buffalo's regular season concludes. But with a Minor League-best .390 average (and a 1.091 OPS) and a .350-plus clip in Triple-A, Guerrero is ready for the highest level. Similar to Jimenez, Guerrero could offer monster fantasy production should he receive a promotion.

3. Victor Robles, OF, Nationals (Previous rank: 6)
Robles is swinging a hot bat in Triple-A, with four multihit performances in his past five games, and he should return to the Majors in September following the conclusion of Syracuse's regular season. The Nats are in a position to give the 21-year-old outfielder an extended audition down the stretch, and he could reward fantasy owners with a solid average as well as plenty of runs and steals.
4. Francisco Mejia, C/OF, Padres (Previous rank: 1)
Mejia has produced a .318/.365/.511 in 23 games with Triple-A El Paso, all while starting exclusively behind the plate. The Padres are intent on keeping the 22-year-old switch-hitter at the position, which is where he offers the most real-life and fantasy upside. However, with El Paso playoff-bound in the Pacific Coast League, Mejia likely will be among the later callups in September.
5. Kyle Tucker, OF, Astros (Previous rank: NR)
Tucker has somewhat surprisingly struggled in the Majors this season, batting .154 over 59 plate appearances in two stints with the Astros. In two games since returning to the Minors, however, the 21-year-old outfielder has gone 7-for-10 at the plate, with three home runs and seven RBIs.
6. Touki Toussaint, RHP, Braves (Previous rank: NR)
Toussaint dazzled during his big league debut on Aug. 13, tossing six strong innings in which he allowed one run on two hits while striking out four. The 22-year-old righty has been exceptional in Triple-A, too, going 4-0 with a 1.62 ERA in seven starts for Gwinnett. The Braves, with their deep crop of young hurlers, will have plenty of options down the stretch, but Toussaint is the most capable to step in and help fantasy owners.

7. Bryse Wilson, RHP, Braves (Previous rank: NR)
Speaking of impressive big league debuts, Wilson, 20, posted five scoreless innings of three-hit ball in his first outing on Monday, earning the win against the Pirates at PNC Park. He was optioned to Gwinnett after the game. To earn his first promotion, Wilson had compiled a 3.27 ERA with 139 strikeouts in 123 2/3 innings across three Minor League levels this season.
8. Alex Verdugo, OF, Dodgers (Previous rank: 7)
Verdugo has cooled off some in Triple-A lately, but the 22-year-old still boasts a .332/.389/.476 line with nine homers over 83 games in the Pacific Coast League. No stranger to the big leagues, Verdugo seems poised to contribute in September for the Dodgers for a second straight year.
9. Peter Alonso, 1B, Mets (Previous rank: 9)
Currently tied for the Minor League home run lead with 32, Alonso might be the top run producer in the Mets' lineup if he were promoted today. In addition to his still growing home-run total, the 23-year-old slugger also has tallied 109 RBIs in 122 games while slashing .278/.394/.560.
10. Justus Sheffield, LHP, Yankees (Previous rank: 8)
The Yankees recently announced that they were moving Sheffield from the rotation to the bullpen at Triple-A Scranton/Wilkes-Barre ahead of his imminent September callup. The 22-year-old lefty was sharp in his first relief appearance, allowing one earned run on two hits with two strikeouts in two innings, and he could offer sneaky fantasy value if called upon to work multiple innings in close games.
Dropped out: Kopech (Previous rank: 5); Ryan Mountcastle, 3B, Orioles (Previous rank: 10)