Check out this All Star game lineup. 1959 AS game.

[maveric]

http://www.baseball-almanac.com/asgbox/yr1959as.shtml
Count the Hall of Famers!

[rurallib]

1. Where the heck were Clemente and F. Robby?

[maveric]

2. Robby was there.

But I didnt see Clemente!!! Maybe he was hurt?

[fishwax]

5. he had a poor start to the season, and then had an arm injury

Even without the arm injury it looks like he wouldn't have made the all star team--batting average of .262 in april and .253 in may: http://www.baseball-almanac.com/players/hittinglogs.php?p=clemero01&y=1959

[KamaAina]

3. Clemente made it the next year.

http://en.wikipedia.org/wiki/Roberto_Clemente

While Clemente had begun to fulfill his potential, the Pirates continued to struggle through the 1950s, although they did manage their first winning season since 1948 in 1959. In 1960, however, the team broke through to a 95-59 record, a National League pennant, and a thrilling seven-game World Series victory over the Mantle-Maris New York Yankees. Clemente batted .310 in the series, hitting safely at least once in every game. His .314 batting average, 16 home runs, and stellar defense earned him his first trip to the All-Star game.

[maveric]

6. Clemente's first great season was 1960.

It was uphill from there.
http://www.baseball-reference.com/c/clemero01.shtml

[Reverend_Smitty]

4. I counted 22 HOFers...

that's an insane number of great players on one field!