Tavares was forced to withdraw from the matchup earlier this week after suffering a knee injury while training that is likely to require surgery and will sideline him for the immediate future.
Lopez (12-1) suffered a split decision loss, the first and only of his 13 bout career, last July, but rebounded to win four-straight, including his most-recent victory in October 2008.
Miller (14-2) is 3-1 in the UFC since making his Octagon debut in 2008, opening with back-to-back wins over David Baron and Matt Wiman before dropping a decision to Gray Maynard in March. The one-time IFL fighter bounced back last month with a unanimous decision win over Mac Danzig at UFC 100.
For the latest UFC 103 rumors check out the MMAFrenzy.com UFC rumors section.
Pictured: Jim Miller