' It is his natural fighter 's instinct to trade punches which has been his Achilles heel and which was his downfall on a couple of occasions when he lost .
His Achilles heel marcos Maidana almost exploited .
' It is his natural fighter 's instinct to trade punches which has been his Achilles heel , which Marcos Maidana almost exploited , and which was his downfall on a couple of occasions when he lost .