rtokens: If he loses Saturday , it could devalue his position as one of the world 's great boxers , " Panamanian Boxing Association President Ramon Manzanares said .
pos: " DT NN PRP VBZ , PRP VBZ IN DT JJ NN IN PRP$ NN .
tokens: " Each time he fights , he 's on the last frontier of his career .
ltokens: But those close to the boxer acknowledge that the man who has won championships in four different weight classes -- lightweight , welterweight , junior middleweight and middleweight -- is drawing close to the end of his career .