I can't find a team where three future hall of famers retired from the same team after the same season. There have been lots of teams with three and more hallof famers on it from Tinkers/Evers/Chance of the 1900 Cubs through the present (By the way, Tinker and Evers absolutely hated each other).

But I don't think Andy Pettite is a Hall of Famer. His 255 wins are more than a stone's throw from the "automatic" win total for hall entry, so other factors are needed. The necessary inquiry is whether he was dominant during his career, and he never led the league in wins, Ks or ERA, and not only did he never win a Cy Young, he never came close in balloting, finishing in the top three only once. He also has only 4 career shutouts. Bartolo Colon has three just this season.

What Pettite has going for him is his winning percentage, but that says as much, if not more, about playing for the Yankees on teams that won a ton of games. He also has more postseason wins than anybody, but you can't compare that honestly with players, who played before 1995 because there is an extra round of playoffs. And players before 1969 never played in any playoffs.

Bert Blyleven was the only pitcher under 300 Ws to make the Hall in 20+ years, and he had 288 for many teams below .500. I think we'll see several other pitchers below 300 Ws make the Hall in the coming years (Pedro, Smoltz and Schilling), but these guys were more dominant pitchers who gave up fewer runs. No current HOF pitcher has a higher career ERA than Pettite's.

And, as mentioned, HGH will also keep him out.

Pettite was a very good pitcher for a lot of years, but not a HOFer.