Bombo Rivera, possessor of one of the best baseball names ever, was one of those guys whose careers started well and then rapidly petered out. Rivera hit .276 as a rookie for the Expos in 1976. His OBP wasn't great and he had little speed, but he slugged .411 and was a young player to watch. Rivera was traded to the Twins after that and had a pretty good year for Minnesota in 1978, hitting .271 as a platoon player against lefties with a good .362 OBP. Rivera was a popular player in the Twin Cities, but it became clear that he just didn't do enough things well enough to really stand out. His power and OBP went up and down and by 1980 he was hitting just .221 while sharing the Twins outfield bench with immortals like Dave Edwards and Willie Norwood. Rivera was with the Royals in 1982 but he got only 10 ABs and one hit during a critical and unsuccessful stretch drive by KC, and the Royals released him at the end of 1983 spring training. Similar players you may know include Chuck Tanner, Bruce Boisclair, Rich Coggins, and Bubba Morton. Rivera has long been a 1980s unicorn, and I am very happy to find him in a KC uniform.
