NBC had high hopes of the new Ron Howard drama, PARENTHOOD, to become an anchor series for the struggling network. But now some sort of medical or health evaluation for the popular actress Maura Tierney, who plays a key role in the series, has put the entire production schedule on hold for as much as eight weeks, likely moving the series to a 2010 release in January.

Tierney has become an important actress in NBC programming with major roles on the moderately popular comedy series, NEWSRADIO and on the long running medical drama, ER. NEWSRADIO fell into a ratings slump after the murder of cast member Phil Hartman. And ER continued to lose cast members after a long run, including Tierney, and concluded it's run a few months ago.

NBC's regular season programming has suffered a ratings beating for the last few seasons, with CBS, ABC and FOX often besting the network. NBC was hoping a revamp of their dramas, including high hopes for PARENTHOOD would improve their regular season ratings. During the Summer season, NBC has been traditionally pretty strong though, with hit series such as AMERICA'S GOT TALENT giving it some strength from the other networks, mostly running rerun programs with fewer Summer season entries.

If health or medical problems for Tierney appear as serious, then that could lead to a serious problem for NBC, as it might be difficult to replace her in the series. For now, the series will only pause and take a break and wait for news on her health situation.