The 32-year-old singer had lined up the 'Bodak Yellow' hitmaker to open his '24K Magic' tour in September but he was in for a shock last week when she announced that she was pulling out of the gigs in order to look after her daughter Kulture - whom she gave birth to two weeks ago - and finding someone to take her place is proving a challenge.
A source told TMZ.com: ''He's without an opener and, so far, there has been no replacement made for Cardi. We're told Bruno's people were burning up the phones Friday ... starting conversations with reps from a number of musicians but nothing is close to being locked down. Cardi's decision to back out of the tour has created some issues ... dancers were hired, costumes made and stage backdrops built.''
However, although it's posing issues now, Bruno seemed supportive of her decision at first and promised her that he would play 'Bodak Yellow' every night just for her.
He tweeted: ''Most important thing is you and your family's health.
''I know the fans will understand. You are absolutely doing the right thing. I also know that we will share the stage when the time is right.
''We love you Cardi and we will play Bodak Yellow every night in your honor. Please give your baby girl a hug from me and a hug on behalf of everyone on The 24K Magic Tour.''