Seattle Mariners rookie outfielder Julio Rodriguez and Cleveland Guardians veteran third baseman Jose Ramirez are the latest participants to join the All-Star Home Run Derby, set for Monday at Dodger Stadium.
Alonso is the two-time defending champion. Others to have entered this year's derby are the Atlanta Braves' Ronald Acuna Jr., the St. Louis Cardinals' Albert Pujols, the Philadelphia Phillies' Kyle Schwarber and the Washington Nationals' Juan Soto.
One spot remains to be filled for the eight-player field.
Rodriguez, 21, led major league rookies with 15 home runs entering Wednesday's games and was third with a .477 slugging percentage. That's after going homerless over his first 20 games and recording his first career home run May 1.
"Since I can remember I've been watching Home Run Derbies every time I get the chance," Rodriguez said. "Since I was a kid I have that dream to play in one, and now that I've got a chance to be in one, it's very surreal that it's happening. I'm just very excited to participate in it."
And his strategy?
"I'm gonna go for homers, man," Rodriguez said.
He is the seventh player in Mariners club history to participate in the Home Run Derby and the first since Robinson Cano in 2016. Hall of Famer Ken Griffey Jr. is the only Mariners player to ever win (three times: 1994, 1998 and 1999).
"It's Julio," Seattle manager Scott Servais said. "I'm sure he'll do well. He'll represent the Mariners very, very well."
Rodriguez, who is hitting .274 with 44 RBIs, 50 runs and 21 stolen bases, was announced as a member of the American League All-Star team on Sunday.
He sat out the opener of the day-night doubleheader in Washington on Wednesday as he served his one-game suspension stemming from his involvement in a brawl with the Los Angeles Angels on June 26. He returned to the lineup for the second game, going 1-for-4 in the Mariners' 2-1 win.
Ramirez, 29, a three-time Silver Slugger Award winner, will be making his fourth All-Star Game appearance next week. He will try to become the first switch-hitter to win the Derby outright after Eric Davis tied for the 1989 crown with Ruben Sierra. Ramirez has 17 home runs this season, 14 of them as a left-handed hitter.
The Associated Press contributed to this report.