Fighters Only Magazine translates an article from Tatame:
"After the first round he [Anderson Silva] said he broke his ribs. He said told me he could not breath because of the rib. I told him to forget the rib and work the movement of legs and he would get the triangle… After the fight he went to the hospital and did an x-ray and the doctor said he did not break it, it was just a crack," Lemos said.
"Anderson is expected to return in February or March."
According to Anderson and his camp the injury existed prior to the fight but was made worse in the first round. Assuming this is true it speaks very highly of Silva that he was able to fight through even a cracked rib for five rounds and then find the desperation submission in the fifth round.
With Anderson on the shelf it should force the UFC into doing a fight like Chael Sonnen vs. Vitor Belfort with the winner getting a title shot rather than keeping one or both men on the sideline until the champion returns. Knowing how the UFC does things, they may even make a Sonnen/Belfort match an interim title bout and then unify when Silva heals. Regardless, the division is hot and interesting for the first time in what feels like forever so the UFC would be wrong to keep their hottest commodities in the division on the shelf.
Ed Soares, Silva's manager, said the following:
I mean, I don't necessarily think an immediate rematch is legitimate. It's not like he won by decision. You got submitted, man. You were on top of him for 23 minutes of the fight and you couldn't finish him. Anderson got a few bumps and bruises, but let's be realistic, you're on a guy 23 minutes and you couldn't finish him? Why should he get a rematch?
Knowing that Silva's camp is going to attempt to play the "you haven't earned your rematch" card it probably makes sense for Sonnen to go in and take a fight with Belfort where he'd likely be heavily favored to win and would eliminate the only other legitimate top challenger for the title.