Gilbreth appeared in two games for the Tigers during the 1972 season, not factoring in a decision while posting a 16.20 earned run average because of his nine earned runs allowed in only five innings of work.
The previous year, his first in the Big Leagues, he fared much better when he posted a 2-1 record over nine games, with an ERA at 4.80, starting five of those appearances and completing two of them.
After missing all of 1973, he was back in Pro Ball in 1974, now with the California Angels, where he started the season in the Minors but make it all the way back to an MLB mound, appearing in three games for California but only tossing 1.1 innings, no decisions, while sporting a rough 13.50 ERA.
Turned out those were his last appearances in professional ball, let alone Major League ball, finishing up with a record of 2-1 along with an ERA at 6.69 over 14 appearances and 36.1 innings pitched.