As much as it messed Williams for losing against Quintana. In all seriousness, Margarito looks like the type of fighter who doesn't let losses afect him.
Depends how he loses really... If he is knocked cold in a few rounds, then it's likely to affect him. If he loses a close disputed decision, then he can look forward to gaining revenge in a rematch. Margarito doesn't seem the type to get all beat up (excuse the pun) about his loses and has bounced back stronger than ever in the past.