Due to a rib injury, UFC middleweight champion Chris Weidman has been forced to withdraw from his UFC 184 main event bout against Vitor Belfort on February 28.



Moving into the main event slot at STAPLES Center in Los Angeles will be the UFC women's bantamweight title fight between champion Ronda Rousey and number one contender Cat Zingano.



The evening's new co-main event will see former world boxing champion and current undefeated bantamweight Holly Holm make her long-awaited UFC debut against number 12-ranked Raquel Pennington.



There is currently no timetable set for Weidman's return to the Octagon.