Katie Taylor defends her WBA women's lightweight title for the first time tonight, barely six weeks after winning it from Inahi Sanchez in Cardiff.
Her eighth professional bout sees her top a professional bill for the first time, following a decorated amateur career.
The 31-year-old meets McCaskill at London's York Hall, having won her first professional title in October on the undercard of Anthony Joshua's defeat of Carlos Takam.
McCaskill, 33 and from Chicago, insists she has discovered "mistakes" in the Irish champion's make-up.
"A lot of the good things you see about Katie Taylor are in highlights," she said. "If you watch the actual fight there is a lot of mistakes.
"There are opportunities there and I intend on taking advantage of that."
During a previous weigh-in for a Katie Taylor bout her opponent, WBA lightweight champion Anahi Sanchez, came in one pound overweight.
Taylor is bidding to make it eight wins in a row since turning professional 13 months ago.
