Mekhi Phifer by Dimitrios Kambouris/WireImage.com Mekhi Phifer by Dimitrios Kambouris/WireImage.com

There's no rest for an ER doc. On Tuesday, Oct. 30, Mekhi Phifer went directly from the birth of his new baby boy, Mekhi Thira Phifer, at 6:47 am to an on-set press conference (anticipating the long-running show's 300th episode), in the early afternoon.

The proud papa announced, "Mekhi Jr. was born this morning at 6:47 am, a beautiful little boy, 5 pounds 4 ounces, and I'm just really excited."

When asked the inevitable question of how hard it was to leave his newborn and his fiancé, Oni Souratha, the baby's mother, Phifer said, "It is, but we gotta keep them bills flowing. Gotta get the bills paid. It's OK, I've just come to knock this out and head on back to the hospital, to relax. Actually I'm off tomorrow, everything's fallen into place like that, so we'll be just fine. And my lady is very excited."

Many congratulated Phifer, including costar John Stamos, who asked what Mekhi Jr. will be called at home, to which Phifer replied, "I don't know Little Man?"

Mekhi Jr. is Phifer's second child. He has an 8-year-old son, Omikaye, from a previous relationship. - Reporting by Carita Rizzo