The welterweight fight adds to the growing Dallas card, which is scheduled to take place at the city's American Airlines Center on March 15.
Gastelum (7-0) comes off a win over Brian Melancon at UFC Fight Night 27, a bout he won in the first round with a rear-naked choke. The fighter was supposed to meet Court McGee at the recent UFC on Fox 9 event earlier this month, but an injury forced him off the card. The fight with Story will be Gastelum's third fight in the UFC, the first being a win over Uriah Hall to win The Ultimate Fighter.
Story (16-7) was once a rising contender in the UFC's 170-pound division. The fighter out of the American Northwest once reeled off six consecutive wins in the Octagon from 2009 to 2011, including a victory over current top contender Johny Hendricks in December 2010. Since then, however, Story has seen mixed results and accumulated a 4-3 record.
UFC officials did not reveal where on the card the Story-Gastulem fight will land. The main card is set to air on pay-per-view.
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