Edwin Diaz, rhp, Mariners: If you're looking for potential breakout prospects for next year, keep an eye on Diaz, a 19-year-old who's currently tearing up the Rookie-level Appalachian League. Diaz allowed only one hit in five innings of work Monday against Bristol. Unfortunately, that one hit followed a pair of walks and was a three-run homer. The rest of Diaz's outing after that second-inning blast was more in line with his season. He retired the next 11 straight Bristol hitters, eight of them via strikeout. Aside from the two walks and homer, only one other hitter reached base against him and that was on an error.
The 6-foot-2 Puerto Rican, who was the Mariners' third-rounder last year, has an explosive arm and has overpowered Appy League hitters to the tune of a league-high 53 strikeouts in 41 innings, to go with a 1.32 ERA. Just as encouraging, he's significantly reigned in his walk rate. It was a small sample, but Diaz handed out 17 free passes in 19 innings (8.05 BB/9) in his pro debut last year. A year later, he's sliced that down to 14 in 41 frames (3.07 BB/9).
Corey Seager, ss, Dodgers: Hamstring issues cost Seager about a month with low Class A Great Lakes in the first half, but he's lived up to his first-round billing since coming back in early June. Seager ranks third in the Midwest League in OPS during the second-half at .998 in 35 games, to go with a .333 average. The 19-year-old arrived in pro ball with a sound swing and developing power, and he showed plenty of it on Monday by homering in his first two at-bats against Lake County, the latter shot a grand slam. It was his third multi-homer game of the season and gives him 11 long balls on the year. He finished the evening 3-for-4, improving his slash line for the season to .308/.383/.517 in 263 at-bats.
Ismael Guillon, lhp, Reds: How do you run up a 6.06 ERA despite a strikeout rate of nearly 11 per nine innings and a .241 opponent average? Answer: When you have Guillon's control issues. The 21-year-old Reds lefty has a solid fastball and devastating changeup, but finding the zone and keeping the ball down have been problems. He's walked 80 in 87 2/3 innings with low Class A Dayton and has a measly 0.51 groundout/air out rate, which contributes his 1.23 HR/9, the third-worst homer rate in the MWL. All that being said, Guillon has shown he can dominate when he's clicking, and he did last night. Guillon struck out eight over 5 2/3 innings against Fort Wayne, allowing one run on three hits and three walks. He moved into second in the MWL strikeout race with 107.
Max Stassi, c, Astros: At the end of the day on July 7, Stassi had hit just four homers all season and was slugging .412 at Double-A Corpus Christi. He went deep the next day and has homered nine more times in the 16 games since. No player from the majors to rookie-ball has gone deep more times than Stassi over that stretch, during which he's hitting .355/.413/.887. This included a streak of five consecutive games with a homer from July 15-21. For all the highlights he's produced this month, Monday against San Antonio might've been Stassi's best night yet. He not only hit a two-run homer in the third but was a force all night, going 4-for-4, adding two doubles and drawing a walk for good measure.
The Athletics made Stassi the richest fourth-round pick ever at the time when they paid him $1.5 million in 2009. They believed he could develops plus raw power, but injuries, particularly shoulder problems, hobbled his career with Oakland and they included him in the deal this past offseason that sent Jed Lowrie to the A's and Chris Carter and Brad Peacock to the Astros. Stassi was then held back by oblique problems this spring and didn't join Corpus Christi until early May. He slumped to a .213 average in June, but his torrid July has upped his season's line to .276/.343/.552 in 210 at-bats, and his 14 homers are one away from his career-high of 15 set last year in high Class A Stockton.
Cody Asche, 3b, Phillies: Maikel Franco's gotten more headlines among Phillies third base prospects, but Asche is who you should expect to see get the call if and when the Phillies deal Michael Young. If that call does come, Asche will carry plenty of positive momentum from Triple-A Lehigh Valley into the majors. He's hit .323/.387/.547 with 10 homers in 52 games since June 1, and he added to it last night with two homers in Pawtucket, giving him 15 for the year.