Yesterday, we told you that Britney Spears would be making an upcoming appearance on How I Met Your Mother.  Unfortunately, her announced entrance was followed by someone else’s exit.

Alicia Silverstone, who was supposed to be involved in a romantic storyline with Ted, has opted out of her guest role.  It seems Alicia didn’t like the idea of Spears’ cameo overshadowing her her spotlight.  (The pop singer was slated to play her receptionist.) 

Sarah Chalke - Dr. Elliot Reid from Scrubs - will now be stepping in to fill the Clueless star’s shoes.  Unfortunately, her schedule will only allow her to be in one episode….not several, as was intended for Silverstone.  This most likely means will not know the identity of the show’s ‘mother’ anytime soon.