The Brewers' Prince Fielder, the Padres' Adrian Gonzalez, the Phillies' Ryan Howard and the Cardinals' Albert Pujols all are scheduled to participate in the Home Run Derby.
Three of the four sluggers have prior Derby experience, while Gonzalez will be making his debut in the event.
Howard won the Derby in 2006 in Pittsburgh, and he competed again in '07 against both Fielder and Pujols in San Francisco. Pujols, who will be in front of his home crowd, was the runner-up to Garret Anderson in the 2003 event at U.S. Cellular Field in Chicago.
Entering Monday's games, Pujols led all of baseball with 31 home runs, and Gonzalez was tied for the second most in the Majors with 24.
Meanwhile, Fielder's 22 home runs are the fourth most in the NL, and Howard's 20 homers rank seventh in the Senior Circuit.
For the first time, fans were allowed to vote for three players to participate in the Derby as part of the State Farm Home Run Derby Fan Poll. Pujols finished first in the NL, followed by Howard and Fielder.
The Derby, part of Gatorade All-Star Workout Day, will be broadcast live on ESPN, ESPN HD, ESPN Deportes and ESPN Radio in the United States beginning at 8 p.m. ET on Monday, July 13. The 80th All-Star Game will be held the following day on Tuesday, July 14.
The four American League participants have yet to be announced.
Rhett Bollinger is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.