Top Rank will be bringing you live video of the weigh-ins for tomorrow night's show in San Antonio on HBO. The weigh-in event starts at 3 p.m. EST at Top Rank's web site, or above in the embedded video.

If you can't watch, join our thread here and we'll give you immediate updates. You should also follow us on Twitter, where we'll be doing the same for all major cards with available live weigh-ins.

In tomorrow night's main event, the WBC middleweight title is on the line, with Julio Cesar Chavez Jr (44-0-1, 31 KO) defending for the second time against Mexican veteran Marco Antonio Rubio (53-5-1, 46 KO).

The televised co-feature will be for the vacant WBA super bantamweight title. Nonito Donaire (27-1, 18 KO) is moving up in weight and looking to capture a title in a third weight class, facing ex-titlist Wilfredo Vazquez Jr (21-1-1, 18 KO).

Top Rank will also be streaming the entire undercard tomorrow, and we'll be covering the full card from 7:30 p.m. EST. Featured players on the undercard include junior middleweight Vanes Martirosyan and welterweight prospect Wale Omotoso.