Like the dwindling field of presidential candidates, the list of witnesses in tomorrow's televised steroids hearing in front of a congressional committee has narrowed. The official start is 10 a.m., and it is being televised in its entirety on C-SPAN3.  For people who don't get C-SPAN3, it will also be on the C-SPAN Web site in streaming video.  Also, an ESPN spokesman said yesterday that beginning at 9:30 a.m., ESPN and ESPN News would be simulcasting the hearings, although it was unclear yet how much of the hearing would be shown.  The ESPN coverage is scheduled to begin at 9:30 a.m.

There will be just two principals, the two chief antagonists -- Roger Clemens and his former personal trainer Brian McNamee.  And a third surprise name, a member of George Mitchell's staff, a lawyer named Charlie Scheeler.

Not on the witness list are Yankees pitcher Andy Pettitte, former MLB player Chuck Knoblauch and Kirk Radomski, the former Mets clubhouse attendant who was just sentenced to probation in federal court for his role in distributing steroids and money laundering.

It would be purely speculative to say why the three are off the hook but its safe to infer that if they could have been of significant help in resolving the gulf of difference between Clemens' and McNamee's versions of reality, they would be testifying.  Radomski has already said he doesn't have first-hand knowledge of Clemens' alleged steroids or human growth hormone use although he has said he finds McNamee believable.

According to reports, Pettitte's information was occasionally contradictory. In all the stories I've read, there's never been a direct-line connection that brought together Knoblauch, Clemens and McNamee, so who can tell exactly why he was a person of interest to begin with.