Looks like Slater Martin and Nate Archibald are your answers to this inquiry. Wow.
9 of the 26 most disappointing playoff efforts coming from Nate and Slater. Havlicek at ages 35 and 36 tossed in a couple clunkers as well.
These two are also on the list of guys who are HOF players and made the all-star team with a PER of under 15 (league average is supposed to always be 15).