Born and raised in Caldwell, Idaho, Reberger graduated from Caldwell High School in 1962 and played college baseball at the University of Idaho in Moscow under head coach Wayne Anderson.
The Vandals won the inaugural Big Sky title in 1964, and again in 1966, and played in the NCAA playoffs for the first time.They eliminated Colorado State College (now Northern Colorado) and Air Force with three straight road victories and advanced to the District 7 finals, today's "super-regionals" (sweet 16).One round from the College World Series, Idaho lost to Arizona in Tucson,which ended their best-ever season at 34–9 (.791).
Undrafted in 1966, he was signed as a free agent by the Chicago Cubs, who had selected Vandal pitching ace Bill Stoneman in the 31st round.
Reberger began his pro career in his hometown with the Treasure Valley Cubs in the Pioneer League in 1966. The following season, he played with the Single-A Lodi Crushers in the California League and the Dallas–Fort Worth Spurs in the Double-A Texas League. He moved up to Triple-A in 1968 with the Tacoma Cubs in the Pacific Coast League.
Reberger made his major league debut with the Cubs in 1968 a day before his 24th birthday, throwing two hitless innings at Wrigley Field on June 6. That October, he was selected by the San Diego Padres in the expansion draft and spent the 1969 season with them. He was traded in December to the San Francisco Giants for Bobby Etheridge, Bob Barton, and Ron Herbel. Rebeger pitched for the Giants in 1970, 1971, and 1972, and for their Pacific Coast League affiliate in Phoenix in 1973 and 1974.