Roberts was born in Vicksburg, Michigan, and attended the University of Michigan, originally recruited to play football by coach Bo Schembechler. He was drafted by Detroit and he was 23 years old when he broke into the big leagues on September 3, 1974, with the Detroit Tigers he earned the dubious honor of replacing Al Kaline in right field for the Tigers.
In the middle of his MLB career, he tried out for the Houston Oilers of the NFL and made the team as an end and punter. He had planned to play only on Sundays and then full-time after the baseball season. The Houston Astros found out his ruse and raised his salary to get him to quit football.
His most productive season came in 1978, when he led the Mariners with a .301 batting average, good for sixth in the American League. In the Opening Game, he belted a grand slam off Minnesota Twins pitcher Geoff Zahn.
On February 5, 1983, Roberts was traded by the Blue Jays to the Royals for a young Cecil Fielder. He also pitched one inning for Kansas City in 1984, giving up three earned runs. He played his last game on September 30, 1984.
At the end of his career, it was discovered that Roberts had seriously bad eyesight due to an accident when he was a child. “I have really bad eyes,” Roberts said, “I stabbed my eye with a knife when I was a kid. I was goofing around with my jackknife. I kept it hidden because I wanted to be a ballplayer. I had a bad focusing point in my right eye and bad depth perception in my left eye, but I kept it secret so I wouldn’t be released. I never told anyone that I had such bad vision in my right eye, not a manager, not a teammate, not anyone. When we had our physicals in spring training there would be a long line, just like a cattle call. I would sneak up and read the line they wanted us to read and memorize it. Then when I got up there I’d just recite what I’d memorized. No one ever figured it out. I would always force myself to really concentrate on reading the ball and tracking the ball.”
Roberts played his final game on September 30, 1984, and he was well-traveled playing for 6 teams during his 11-season career, Roberts posted a batting average of .267 (731-for-2,737) with 78 home runs and 328 RBI in 901 games played. Following his professional playing career, he began a career managing in the Minor Leagues.
In between, Roberts played winter ball with the Leones del Caracas club of the Venezuelan League during the 1977–1978 season.
Leon Roberts holds the major league record for most home runs by a player born on January 22nd (78).
In 1989, Roberts played for the Winter Haven Super Sox of the Senior Professional Baseball Association and later replaced Ed Nottle as the club’s manager. He hit .290 with 8 homers and 44 RBI in 65 games for the club. In 1990, he played for the San Bernardino Pride of the SPBA. He played in 25 games and was batting .300 with 3 home runs and 22 RBI when the league folded.
Roberts has also bounced around as a coach for a dozen MLB franchises. Roberts’ brother, Bill Roberts, was an outfielder in the Houston Astros chain.