Acquired from the Mariners at the Trade Deadline in the Marco Gonzales deal, O'Neill batted .253/.304/.548 with 12 home runs in 37 games with Memphis after the trade. Overall, the 22-year-old outfielder slugged 31 homers in 130 Triple-A games, marking his second 30-homer campaign in the past three seasons.
He's hitting .250 with seven RBIs in the postseason.
The rest of the best performances from top prospects Saturday
• No. 7 overall prospect Brendan Rodgers (Rockies' No. 1) and Garrett Hampson (No. 8) combined for five runs, four hits, three RBIs and four walks as Class A Advanced Lancaster defeated Rancho Cucamonga to advance to the California League finals. Rodgers went 2-for-5 with three RBIs as the team's designated hitter, while Hampson finished 2-for-3 with three walks and three runs scored out the leadoff spot.
• No. 12 overall prospect Brent Honeywell (Rays' No. 1) wasn't at his best, giving up three earned runs on nine hits in 6 1/3 innings, but he pitched well enough for Triple-A Durham to eventually claim a 4-3 win over Indianapolis and a trip to the International League finals. The 22-year-old right-hander struck out three and walked one.
• No. 58 overall prospect Fernando Tatis Jr. (Padres' No. 4) went 2-for-5 with a double and one run scored out of the leadoff spot as Double-A San Antonio fell to Midland, 6-3, in Game 4 of the Texas League semifinals. The 18-year-old infielder is hitting .421 (6-for-16) with four runs scored in the series, which comes down to a decisive Game 5 on Sunday.
• No. 74 overall prospect Adrian Morejon (Padres' No. 5) turned in a quality start for Class A Fort Wayne against Dayton in the Game 1 of the Midwest League semifinals. Working six innings, the 18-year-old left-hander allowed one earned run on seven hits with two walks and five strikeouts, though the TinCaps lost the game, 2-1.
• A's No. 4 prospect Jorge Mateo delivered a go-ahead bases-clearing double in the bottom of the eighth inning to lead Double-A Midland past San Antonio, 6-3, and force a decisive Game 5 in the Texas League semifinals. The 21-year-old shortstop did a little bit of everything in the game, going 3-for-5 with two runs scored and two stolen bases out the leadoff spot along with the game-winning hit.
• A's No. 16 prospect Greg Deichmann plated a pair of runs with a solo home run and a sacrifice fly to finish 1-for-2 as Class A Short Season Vermont beat Mahoning Valley, 8-3, in Game 1 of the New York-Penn League semifinals. The 2017 second-rounder from LSU had a strong pro debut, hitting .274/.385/.530 with eight homers and 30 RBIs in 46 games.
• Dodgers No. 30 prospect Matt Beaty powered Double-A Tulsa in a 16-8 win over Northwest Arkansas to force a decisive Game 5 in the Texas League semifinals. Batting third for the Drillers, Beaty piled up four runs, two doubles and an RBI while going 4-for-5. He's batting .412 in the series.
• Indians No. 10 prospect Willi Castro went 3-for-5 with two RBIs as Class A Advanced Lynchburg defeated Frederick, 7-1, to become Mills Cup co-champions. The 20-year-old shortstop batted .308 with one home run and three RBIs in the series after slashing .290/.337/.424 with 38 extra-base hits and 19 stolen bases in 123 games with the Hillcats during the regular season.
• Red Sox No. 11 prospect Bobby Dalbec connected on a three-run homer in the eighth inning of Class A Greenville's 5-0 victory over Charleston in the South Atlantic League semis. Right-hander Hildemaro Requena (No. 29) paced the Drive on the mound, tossing 7 1/3 scoreless innings of four-hit ball with three walks, four strikeouts and 12 ground-ball outs. Greenville leads the best-of-five series, 2-1.
• Royals No. 14 prospect Ryan O'Hearn blasted a three-run homer for Double-A Northwest Arkansas in its 16-8 loss to Tulsa in Game 5 of the Texas League semifinals. Center fielder Donnie Dewees Jr. (No. 18) went 2-for-4 and scored three runs out of the leadoff spot.
• Yankees No. 18 prospect Thairo Estrada turned in another multihit game, and it helped lead Double-A Trenton past Binghamton, 9-1, and into the Eastern League finals. He went 3-for-4 with two runs scored and two RBIs, two days after he hit for the cycle and drove in three. The 21-year-old shortstop batted .500 (8-for-16) with five runs and five RBIs in the four-game series.