[5] Wakamatsu was a three-sport star at the Bay Area's Hayward High School in California, and ultimately chose baseball over football due to his lack of size.

Shortly after the Reds released him, he signed with the Chicago White Sox, who assigned him to the Double-A Birmingham Barons.

Wakamatsu played 18 games in the majors as a backup catcher for the White Sox in 1991,[7] working in all of his starts for knuckleballer Charlie Hough.

After the 1991 season the White Sox granted Wakamatsu free agency, and he signed with the Los Angeles Dodgers shortly after.

[8] On April 6, 2009, Wakamatsu won his managerial debut as the Mariners beat the Minnesota Twins 6–1 on Opening Day.

[11] On November 8, 2010, Wakamatsu was announced as the new bench coach for the Toronto Blue Jays, under new manager John Farrell.

[13] On April 19, 2015, Wakamatsu was one of five Royals (also pitching coach Dave Eiland, manager Ned Yost, pitcher Kelvin Herrera and shortstop Alcides Escobar) to be ejected in a game against the Oakland Athletics.

Two games prior, Escobar had been injured following an attempt by A's third baseman Brett Lawrie to break up a double play.

Considering the slide a dirty one, Royals pitcher Yordano Ventura hit Lawrie in the elbow the following game and was immediately ejected.

He resides in North Richland Hills, Texas with wife, and their three children, sons Jacob and Lucas and daughter Jadyn.

[24] His paternal great-grandparents emigrated from Japan to Orting, Washington in the early 20th century and settled in Hood River, Oregon, where Wakamatsu was born.

His father was born in the Tule Lake War Relocation Center, a Japanese American internment camp located in Northern California near the Oregon border.