In real-life MLB,
Paul Schreiber once had a 22-year wait in between two games pitched.
In the fictional ABL, the record for time-gaps in appearances are less extreme but no less cruel. The record in my league belongs to Cesar Rosario, with thirteen years, and thirteen 1-year contracts signed in between.
From what I can tell, many of the players on this list were middling AAA-level relievers who were lucky enough to be called up twice. On the other hand, Greg Morton was a first-round draft pick with high expectations. He was ranked as high as the #43 prospect in the ABL. Scouts had him pinned as a starter, but he could never really cut it.
After a few seasons of subpar relief, most pro teams gave up on Greg. He was granted a home in Las Vegas's minor league system for nearly ten years before he made his return to the promised land. 10 years waiting made no difference, Greg was still a subpar reliever.