[1] He played his entire career in Major League Baseball (MLB) for the Kansas City Royals from 1976 to 1985.

Wathan was a member of the world champion 1985 Kansas City Royals team.

Wathan had his best season in 1980 in which he played in 126 games, and had a .305 batting average with 6 home runs and 58 RBI.

[5] In 1992, Wathan began the season as the third-base coach of the California Angels, but he was named acting manager midway through the campaign when Buck Rodgers was badly hurt in a bus accident and took a medical leave of absence.

In 2006-07, Wathan was a roving baserunning and bunting instructor in Kansas City's farm system, and in 2008 he served the Royals as a special assistant to the director of player development.