After six seasons in their farm system, in which he batted .275 with 47 home runs and 274 RBIs, he made his major league debut on April 13, 1976.

On June 15, 1977, the New York Mets traded Tom Seaver to the Cincinnati Reds for Pat Zachry, Doug Flynn, Steve Henderson and Dan Norman, and Dave Kingman to the San Diego Padres for Bobby Valentine and minor league pitcher Paul Siebert.

To make room for Youngblood on the Mets' active roster, player-manager Joe Torre retired as a player.

[4] With the Mets, Youngblood emerged as something of a "star" on the team that consistently finished last or close to it throughout his time in New York City.

Not only had he been traded, but the Expos had requested Youngblood make himself available for their game later that evening in Philadelphia as they were particularly short handed on players.

Facing another future Hall of Famer in Steve Carlton, Youngblood reached on an infield single when Manny Trillo could not field the ball cleanly.

After one season back with the Reds, Youngblood joined the Sun City Rays of the Senior Professional Baseball Association in 1990.

[10] After serving as a minor league outfield and baserunning coordinator, Youngblood joined the Diamondbacks as third base coach on July 3, 2010.