Who are the minor league players that hit 3 home runs in a single inning?

Answer 1

It's been done by numerous players, most recently on October 19, 2017 by Kiké Hernadez of the Los Angeles Dodgers in a pennant-clinching game against the Chicago Cubs. The Dodgers won 11-1 at Chicago's Wrigley Field to advance to the 114th World Series.

The last person to hit four home runs in a game was J.D. Martinez of the Arizona Diamondbacks on September 4, 2017. Martinez paced the Diamondbacks to a 13-0 rout of the Los Angeles Dodgers at Dodger Stadium. He became the 18th player in baseball history to accomplish the feat. Three months earlier, on June 6, 2017,, Cincinnati Reds left fielder Scooter Gennett hit four homers in a 13-1 victory over the St. Louis Cardinals in Cincinnati.

The last person to hit three homers in a World Series game was Pablo Sandoval of the San Francisco Giants. On October 24, 2012, Sandoval hit three homers for the Giants in Game 1 of the 108th World Series. Sandoval's blasts paced the Giants to an 8-3 win over the Detroit Tigers at AT&T Park in San Francisco.Sandoval hit a solo home run in the first inning and a two-run homer in the third off Detroit ace Justin Verlander. The Giants third baseman later hit another solo shot, this time victimizing Tigers reliever Al Alburquerque. Sandoval joined Babe Ruth, Reggie Jackson and Albert Pujols as the only players to have three-homer games in World Series competition. Ruth hit three homers in a Series game twice.
Pujols' three-homer game in the 2011 World Series was the fifth of his career. He is one of six players to have exactly five three-homer games. The others: Alex Rodriguez, Dave Kingman, Joe Carter, Mark McGwire and Carlos Delgado. Two players -- Johnny Mize and Sammy Sosa -- pulled off the feat six times, and Sosa did it three times in 46 days (on August 9, August 22 and September 23 in 2001).
The Yankees' Rodriguez hit three homers on July 25, 2015 -- two days before his 40th birthday. He became the fifth-oldest player in history to accomplish the feat, trailing Stan Musial (who did it at age 41), Jason Giambi (40), Reggie Jackson (40) and Babe Ruth (40).

Answer 2

Fernando Tatis, Babe Ruth, Ryan Howard, Raul Ibanez, Willie Mays, Jay Bruce, Gene Rye, and Andrew McCutchen