Man I thought Longo was going to be an easy HoFer. 45.7 fWAR through age-30, then just 9 in the 7 years since.
Another 3B in a similar boat is Jose Ramirez. 46.7 fWAR through age-30. He's like two-more 5-win seasons from getting to slam-dunk territory, and can also get in if he has a run of good but not great seasons into his mid-late 30s. Probably helps if he plays his whole career in Cleveland.