Just after Thiago Silva knocked out Rafael Cavalcante for his first win in four years, his former teammate Antonio Silva laid out a challenge for him. According to Bigfoot, who posted on Twitter, the two have a debt to settle, and he said that Silva, who cuts down from around 230 pounds to make the light-heavyweight limit, should fight him as a heavyweight.No can do, responded Thiago Silva, who declined the invitation. Antonio Silva did not elaborate on the source of the tension between them, but Thiago offered up a theory, as well as proposing a counteroffer.He must be sad because I left American Top Team, but if he wants to fight me he has to come down to 205. That‘s it, he said through an interpreter at the UFC on FUEL 10 post-fight press conference. Thiago Silva, who is 6-foot-2 with a 74-inch reach, has spent his entire career competing in the 205-pound weight class.By comparison, Antonio Silva is 6-foot-4 with an 82-inch reach. He routinely cuts down from over 265 pounds to make the heavyweight limit. Just a few weeks ago, he lost to Cain Velasquez via TKO in a UFC heavyweight championship match. Thiago Silva won a double bonus at UFC on FUEL 10, earning Knockout of the Night honors for his first-round finish of Cavalcante, along with Fight of the Night. The two awards left him with a cool $100,000 in bonuses. Any fight between the two seems a remote possibility. After getting back into the win column for the first time since 2009 (two presumptive wins in the interim were later changed to no contests due to flunked drug tests), Thiago Silva now has options in his division, while Antonio Silva has neither the inclination nor any realistic chance of moving down to light-heavyweight.