where's Jerry Nelson?

When the opening credits beriefly listed the Muppet performers, I didn't see Jerry, but then I couldn't catch all the names anyway.

But then the moment they showed Statler and Waldorf, and I didn't hear Jerry's voice, I knew he was missing from the movie. That meant no original Lew Zealand voice, no original Crazy Harry voice, etc. (no wonder I didn't hear them speak in the movie)

Anybody have any theories why Jerry was absent? Did he quit the Muppets altogether?