Here's MLB Pipeline's roundup of the top prospect performances in the Minor Leagues on Monday.
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It hasn't taken Ryan Helsley long to find his groove at the Triple-A level.
The Cardinals' No. 4 prospect allowed an unearned run in the first inning before settling in and completing seven innings in Memphis' 2-1 win over Colorado Springs.
Helsley permitted a baserunner in each of the first four frames but retired the final 11 batters he faced, four via strikeout, following a one-out double in the fourth inning. The right-hander ultimately allowed three hits, issued one walk and struck out 10 in the outing, throwing 70 of his 106 pitches for strikes.
Helsley's 10 strikeouts on Monday matched his season high, as he previously accomplished the feat with Double-A Springfield on May 5. It also marked the fifth time in 59 career starts that the 23-year-old has punched out double digits.
Video: Top Prospects: Ryan Helsley, RHP, Cardinals
After earning his first Triple-A win in an April 29 spot start for Memphis (7 IP, 4 H, ER, BB, 9 K's), Helsley has returned to the Pacific Coast League to allow two earned runs on five hits while compiling 19 strikeouts across back-to-back seven-inning starts. Altogether, Helsley owns a 1.29 ERA with a 0.57 WHIP and 28-to-3 strikeout-to-walk ratio in 21 Triple-A innings.
A fifth-round Draft pick in 2015, Helsley, the Florida State League Pitcher of the Year in '17, was promoted to the Minors' highest level after he posted a 4.39 ERA with 44 strikeouts over 41 innings (seven starts) in the Double-A Texas League.
The rest of the best performances from top prospects Monday:
• No. 2 overall prospect Vladimir Guerrero Jr. (Blue Jays' No. 1) started the scoring for Double-A New Hampshire with a first-inning RBI double that also extended his on-base streak to 36 games. He finished the game 2-for-4, marking his 26th multi-hit performance this season. The 19-year-old phenom is leading the Minor Leagues in average (.433), hits (77) and RBIs (50) and owns an incredible 1.194 OPS with 10 home runs and 18 doubles through 46 games.
Video: Top Prospects: Vladimir Guerrero Jr., 3B, Blue Jays
• No. 9 overall prospect Michael Kopech (White Sox No. 2) allowed two or fewer earned runs for the third time in as many starts for Triple-A Charlotte. The 22-year-old flame-thrower gave up a pair of earned runs on three hits in six innings, issuing two walks and striking out seven. Kopech lowered his ERA to 3.86 with the performance, and he's now compiled 68 strikeouts against 25 walks in 51 1/3 frames (10 starts), while holding hitters to a .198 average.
Video: Top Prospects: Michael Kopech, RHP, White Sox
• No. 15 overall prospect Kyle Tucker (Astros' No. 2) was 3-for-3 with two doubles, two runs scored and four RBIs through the first three innings of Triple-A Fresno's rout of El Paso. He ultimately reached base in each of his five plate appearances, also drawing a pair of walks in the contest while snapping an 0-for-12 skid at the plate. The 21-year-old outfielder is putting up strong numbers in the Pacific Coast League, with a .282 average, six home runs, 16 doubles and 37 RBIs through 46 games.
Video: Top Prospects: Kyle Tucker, OF, Astros
• No. 42 overall prospect Justus Sheffield (Yankees' No. 3) was sharp in another abbreviated start for Triple-A Scranton/Wilkes-Barre, his second since returning from a stint on the disabled list with shoulder tightness. Throwing 75 pitches (49 strikes) over four innings, the 22-year-old lefty allowed one earned run on four hits while walking two and striking out four. Sheffield has posted eight innings of one-run ball with nine strikeouts since coming off the shelf, giving him a 1.65 ERA in 16 1/3 innings (four starts) at the Triple-A level.
Video: Top Prospects: Justus Sheffield, LHP, Yankees
• No. 63 overall prospect Kyle Lewis (Mariners' No. 1) connected on his first home runs of the season, hitting a three-run shot in the fourth inning and then adding a two-run blast in the sixth to help power Class A Advanced Modesto past Stockton. It was the second career multi-homer game for Lewis, who finished with a career-best four hits (4-for-5) to record his third multi-hit performance during his six game-hitting streak. Finally healthy after an offseason procedure on his problematic right knee cost him the first month-plus of the season, Lewis has kicked off his campaign by hitting .302 with seven extra-base hits and nine RBIs in his first 13 games.
Video: Top Prospects: Kyle Lewis, OF, Mariners
• No. 87 overall prospect Ryan Mountcastle (Orioles' No. 2) hit his third home run of the season, a two-run shot in the fourth inning, accounting for all of Double-A Bowie's offense in a 3-2 loss to Binghamton. While a broken hand suffered during Spring Training delayed the start of Mountcastle's season until May 10, the 21-year-old third baseman quickly has made up for lost time by slashing .294/.342/.471 with six extra-base hits and 16 RBIs in his first 18 games.
Video: Top Prospects: Ryan Mountcastle, 3B, Orioles
• Braves No. 18 prospect Drew Waters went 2-for-4 with a walk, a run scored and a stolen base out of the leadoff spot for Class A Rome. After a rocky start to the season (.237/.297/.424 in April), the 2017 second-rounder is slashing .313/.370/.657 with five home runs over 17 games this month. With a .278/.336/.548 batting line, six homers and six steals through 32 games, Waters, a 19-year-old outfielder, is a candidate to go 20-20 in his first full season.
• Dodgers No. 29 prospect Rylan Bannon connected on his 10th home run and went 3-for-4 with three RBIs in Class A Advanced Rancho Cucamonga's loss to Lake Elsinore. Bannon's homer, a two-run shot in the third inning, was his second in 25 games this month after the 22-year-old third baseman blasted eight homers over 23 games in April. An eighth-round pick last June, Bannon has produced a .281/.375/.534 slash line with 22 extra-base hits in 48 games with the Quakes.
• Rays No. 9 prospect Justin Williams hit a solo home run and scored a pair of runs before finishing 3-for-4 in Triple-A Durham's win over Louisville. It was the fifth home run of the season for the 22-year-old outfielder, and he's now tallied three hits in two of his past four contents. In his first Triple-A exposure, Williams has produced a .253/.320/.403 batting line with 13 extra-base hits in 43 games.
Video: Top Prospects: Justin Williams, OF, Rays
Right-handed relievers Diego Castillo (No. 27) and Ian Gibaut (No. 29) struck out three batters each while posting a combined 3 2/3 scoreless innings out of the Bulls' bullpen. Gibaut, 24, lowered his ERA to 0.76 with the performance and sports a 0.63 WHIP with 31 strikeouts and three walks through 23 2/3 frames (18 appearances) on the season. The 24-year-old Castillo, meanwhile, owns a 0.74 ERA and 0.78 WHIP, with 27 strikeouts and six walks in 24 1/3 innings (18 appearances). Together, the late-inning duo has combined to limit batters to 25 hits (1 HR) in 48 innings.
• Twins No. 6 prospect Alex Kirilloff went 2-for-4 with a solo home run, though it wasn't enough to keep Class A Cedar Rapids from falling to Clinton, 4-3, in 10 innings. After missing all of 2017 while recovering from Tommy John surgery, Kirilloff, a 20-year-old outfielder who the Twins selected in the first round in '16, has opened his first full season by slashing .318/.373/.572 with eight homers, 14 doubles and 38 RBIs in 45 games.
Video: Top Prospects: Alex Kirilloff, OF, Twins
• White Sox No. 18 prospect Luis Gonzalez homered out of the leadoff spot for the second time as Class A Kannapolis edged West Virginia, 2-1, in a rain-shortened game. The 2017 third-rounder is raking at a .392 clip with 10 extra-base hits (of his 20 hits) during his current 13-game hitting streak. Overall, Gonzalez ranks second in the South Atlantic League in average (.339), OPS (.972), hits (59) and total bases (100).
Mike Rosenbaum is a reporter for MLB.com. Follow him on Twitter at @GoldenSombrero.