McReynolds was drafted by the Milwaukee Brewers after his senior year of high school, but chose to attend the University of Arkansas where he played outfielder for the Razorbacks under scholarship.

That year Arkansas came in second in the College World Series in which McReynolds hit for a .566 batting average, with two home runs, two doubles and five RBIs.

In his junior year, McReynolds hit for a .386 batting average with 17 home runs and 57 RBIs as the Razorbacks finished second in the league and received a berth in the NCAA tournament.

The San Diego Padres selected McReynolds with the sixth pick in the first round of the 1981 Major League Baseball draft.

McReynolds played for the Class A-Advanced Reno Padres in Nevada, the Double-A Amarillo Gold Sox in Texas, and then the Triple-A Las Vegas Stars.

McReynolds made his major league debut for the Padres on June 2, 1983, against the Philadelphia Phillies; he hit a home run in his fourth at-bat.

McReynolds along with rookie outfielder Carmelo Martínez was hyped as the M&M Boys after the New York Yankees 1960s power-hitting duo of Mickey Mantle and Roger Maris.

During the 1984 National League Championship Series (NLCS) McReynolds had a .300 batting average, hit 1 home run and 4 RBIs.

On December 6, 1991, the Mets traded McReynolds, along with Gregg Jefferies and Keith Miller, to the Kansas City Royals for Bret Saberhagen.