The Bay Area rivals' Triple-A squads will face off for the Pacific Conference title in a best-of-5 series.
On the other side of the bracket, the American Conference championship will come down to the Round Rock Express and Iowa Cubs. Neither team has won a title, with Round Rock losing in the Finals twice (2006, 2015) since joining the PCL in 2005 and Iowa losing once to Sacramento (2004) since coming aboard in 1998.
Round Rock Express (84-56, American Southern Division champion) vs.
Iowa Cubs (75-65, American Northern Division champion)
Round Rock won season series, 11-5
Game 1 at Round Rock, Sept. 4 at 8:05 p.m. ET
Game 2 at Round Rock, Sept. 5 at 8:05 p.m. ET
Game 3 at Iowa, Sept. 6 at 8:08 p.m. ET
Game 4 at Iowa, Sept. 7 at 8:08 p.m. ET (if necessary)
Game 5 at Iowa, Sept. 8 at 1:08 p.m. ET (if necessary)
An unbalanced season series between the teams does not necessarily portend an easy opening round for the Express.
Iowa has an interesting blend of veterans and prospects trying to get the team back to the Finals for the first time in 15 seasons. First baseman Jim Adduci (.301/.338/.465, 12 homers, 58 RBIs), third baseman Phillip Evans (.283/.371/.470, 17 homers, 61 RBIs) and shortstop Dixon Machado (.261/.371/.480, 17 homers, 65 RBIs) have brought a combined 357 games of Major League experience to the Cubs.
Shortstop Zack Short (.211/.338/.414, six homers, 17 RBIs) is the Cubs' No. 9 prospect and has been with Iowa for 41 games after missing time due to injury. Second baseman Trent Giambrone (.241/.314/.465, 23 homers, 66 RBIs, 17 stolen bases) has been a rock this season, befitting his No. 28 prospect status.
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Iowa's pitching staff is led by PCL Pitcher of the Year Colin Rea (14-4, 3.95 ERA), with support from Matt Swarmer (10-11, 5.65) in the rotation and Dillon Maples (4-4, 3.77, seven saves) in the bullpen.
Round Rock fended off a season-long challenge from its new in-state rival, San Antonio, overcoming key players being promoted or traded, including Yordan Alvarez, Josh Rojas, Derek Fisher and Kyle Tucker.
There's still plenty of talent on the roster, led by first baseman Taylor Jones (.291/.388/.501, 22 homers, 84 RBIs), middle infielder Jack Mayfield (.287/.350/.566, 26 homers, 79 RBIs), third baseman Nick Tanielu (.295/.360/.520, 19 homers, 84 RBIs) and outfielder Drew Ferguson (.281/.395/.440, 11 homers, 57 RBIs, 27 steals).
The Express' pitching staff is led by Astros Nos. 10 and 11 prospects Cristian Javier (1.64 ERA in two starts) and Brandon Bielak (8-4, 4.41), plus 22nd-ranked Rogelio Armenteros (6-7, 4.80). The bullpen is anchored by Ralph Garza (8-1, 4.04, five saves) and Brendan McCurry (3-5, 4.23, six saves).
Las Vegas Aviators (83-57, Pacific Southern Division champion) vs.
Sacramento River Cats (73-67, Pacific Northern Division champion)
Las Vegas won season series, 11-5
Game 1 at Sacramento, Sept. 4 at 9:35 p.m. ET
Game 2 at Sacramento, Sept. 5 at 9:35 p.m. ET
Game 3 at Las Vegas, Sept. 6 at 10:05 p.m. ET
Game 4 at Las Vegas (if necessary), Sept. 7 at 10:05 p.m. ET
Game 5 at Las Vegas (if necessary), Sept. 8 at 3:05 p.m. ET
The Aviators won 10 of the first 12 meetings with the River Cats before Sacramento took three of four in Las Vegas from June 21-24. That was the last meeting of the season between them, so plenty has changed for both clubs.
"There's been a lot of roster turnover for both teams since then," Aviators manager Fran Riordan said. "There's gonna be guys not familiar with each other. But our guys have weathered a lot of bumps in the road. They're a resilient bunch."
Among the most prolific Las Vegas players still on the roster are outfielders Mark Payton (.334/.400/.653, 30 homers, 97 RBIs), Dustin Fowler (.277/.333/.477, 25 homers, 89 RBIs) and Skye Bolt (.269/.350/.459, 11 homers, 61 RBIs) and shortstop Jorge Mateo (.289/.330/.504, 19 homers, 78 RBIs, 24 stolen bases), the A's No. 4 prospect.
The team has been augmented by a number of young players promoted from Double-A Midland and Class A Advanced Stockton. Two of them -- Mikey White and Alfonso Rivas -- played key roles in Sunday's division-clinching win.
"Having guys prepared to play at this level, that's what it's all about," Riordan said. "Mikey White tied the game with a home run and Alfonso Rivas hit the go-ahead home run."
The Aviators' playoff rotation starts with veteran right-hander Daniel Mengden (4-3, 4.22 ERA), followed by Parker Dunshee (4-5, 5.38) and top A's prospect Jesus Luzardo (1-1, 3.19 in seven starts). If Games 4 and 5 are necessary, two other late-season promotees will start in righties Grant Holmes and James Kaprielian.
"The best part about those guys [Holmes and Kaprielian] is they're not scared," Riordan said.
Sacramento is a formidable opponent, led by outfielder Mike Gerber (.308/.368/.569, 26 homers, 83 RBIs). The River Cats' pitching staff is something of a patchwork group, however, with only Enderson Franco (6-5, 5.97) having thrown more than 60 innings at Triple-A.
Old affiliates, new affiliates: In terms of the length of affiliation, Iowa and the Cubs have been together for 38 years, the second-longest pact in the PCL behind only Omaha and the Royals (1969). In contrast, the Giants and Sacramento have been together since 2015, while Las Vegas and the A's are in their first season as affiliates. Round Rock and the Astros are in a second affiliation that started this season; the first lasted from 2000-10.
All-Stars on the rise: The only member of the All-PCL team who's participating in the postseason is Rea, the Pitcher of the Year. Tucker would have been in the Round Rock lineup, but the Astros recalled him on Monday. In fact, most of the All-PCL team is in the Majors, including catcher David Freitas (Brewers), first baseman Kevin Cron (D-backs), second baseman Isan Diaz (Marlins), third baseman and MVP Ty France (Padres), outfielders Yonathan Daza and Sam Hilliard (both Rockies) and designated hitter Jared Walsh (Angels).
Called up: A few other notable performers were called up by their big league affiliates over the weekend. The Cubs brought up right-handers Adbert Alzolay and Alec Mills, catcher Tyler Davis, second baseman Robel Garcia and outfielder Albert Almora Jr. The Astros also promoted catcher Garrett Stubbs and lefty Cionel Perez. The A's added righty Paul Blackburn, catcher Sean Murphy and infielder Franklin Barreto. Giants callups included southpaw Conner Menez, righty Burch Smith, catcher Aramis Garcia and first baseman/outfielder Chris Shaw.