Why is Sergio Martinez is fighting another unknown and unranked Middleweight fighter Darren Barker?

Well right now he has been claiming that he will not fight above 160, but when he soon realizes that there is nobody other than Felix Sturm, who refuses to fight anyone with a pulse, there is nobody at 160 that is good enough to fight. Arum would never put Chavez Jr. up against Martinez, too much risk too little reward. Cotto is a draw in New York and has potential fights with Margarito and Chavez and has too much to loose by fighting a much bigger and as well faster middleweight. Martinez will be fighting at 160 maybe for two more fights, until he turns it up to the hottest division in boxing at 168 with guys like Froch, Ward, Bute, Kessler, Dirrell, and Abraham.