CHICAGO -- A farm system that Mariners general manager Jerry Dipoto is looking to beef up after taking over the reins in Seattle this season has received a boost from the arrival of two new players in MLBPipeline.com's midseason Top 100 Prospects list.
Seattle opened the year with just one player in the Top 100 preseason list -- 2014 first-round Draft choice Alex Jackson was No. 94. But while Jackson has dropped off the updated list, 2016 first-round Draft pick Kyle Lewis debuted as the No. 40 prospect, while hot-hitting outfielder Tyler O'Neill jumped in at No. 74 after a strong first half for Double-A Jackson.
Lewis, 21, won the Golden Spikes Award as the best college player in the nation last year as a junior at Mercer University. He was the 11th overall pick in the 2016 MLB Draft, and Lewis received his strong ranking despite suffering a season-ending right knee injury on July 19 that sideswiped his initial pro season for Class A Short-Season Everett.
Lewis tore his anterior cruciate ligament in a home-plate collision on July 19, but the injury did not affect his rating, because it doesn't impact his long-term value. He had posted a .299/.385/.530 line with 16 extra-base hits and 26 RBIs in 30 games.
The Mariners asked O'Neill, a 21-year-old Canadian who was a third-round Draft pick in 2013, to become a more patient and better all-around hitter -- he batted .260 with a .316 on-base percentage, while slugging 32 homers and 87 RBIs for Class A Advanced Bakersfield last year -- and he has responded with a big season that earned him a spot in the SiriusXM All-Star Futures Game.
O'Neill has put up a .301/.370/.536 line with 19 homers and 76 RBIs in 94 games for Jackson -- where he is one of the youngest players in the Southern League.

MLBPipeline.com also updated the Top 30 Prospects list for each club, and the Mariners saw some significant movement there, with Lewis taking over the top spot, previously held by Jackson.
Jackson, a 20-year-old outfielder who was the sixth overall Draft pick in 2014, dropped to No. 6. He is hitting .242 with nine homers and 41 RBIs in 59 games for Class A Clinton.
Shortstop Drew Jackson, a fifth-round Draft pick out of Stanford in 2015, remains No. 3, while young right-hander Nick Neidert, the 2015 second-round pick, moved up three spots to No. 4. Lefty Luiz Gohara remained in the fifth spot.
Two recently acquired Cubs prospects have bolstered the Mariners' rankings, as first baseman Dan Vogelbach comes in at No. 7 and right-hander Paul Blackburn is at No. 17.
Additionally, second-round Draft pick Joe Rizzo, a third baseman out of the Virginia prep ranks, enters the Mariners' list at No. 9 and shortstop Bryson Brigman is at No. 15. Right-hander Zach Lee, acquired from the Dodgers, is listed as Seattle's No. 28 prospect.
Outfielder Boog Powell, who is serving an 80-game suspension, fell from No. 8 to 19.
The ranking of baseball's top prospects is done by MLBPipeline.com Draft and prospect experts Jonathan Mayo, Jim Callis and Mike Rosenbaum, who compile input from industry sources, including scouts and scouting directors. It is based on analysis of players' skill sets, upsides, proximity to the Majors and potential immediate impact to their teams. Only players with rookie status are eligible for the list. The rankings follow the Collective Bargaining Agreement guidelines for which players fall under the international pool money rules: Players who were at least 23 years old when they signed and played in leagues deemed to be professional (Japan, Korea, Taiwan, Cuba) are not eligible.