Bruno Mars scrambling to replace Cardi B on tour

EXCLUSIVE

Bruno Mars was just as shocked as everyone by the news Cardi B withdrew from the tour with him to take care of his baby … and now his act of opening because its imminent tour is totally in the air.

Sources related to Bruno's tour – scheduled for the kickoff in September – tell us that he is without an opener and, until now, there is had no replacement done for Cardi. We are told that Bruno 's people were burning phones Friday … starting conversations with representatives of several musicians, but nothing is close to being locked.

Our sources say that Cardi's decision to withdraw from the tour created problems … dancers were hired, costumes were made and backdrops were made.

As we reported … Cardi abandoned his concert with Bruno because she "underestimated all that mom thing". She told the fans that she needed more time to recover and that she was not ready to part with her daughter, Kulture, while she was taking the road .

Mars responded with a heartfelt message of support and understanding, adding … "We love you Cardi and we will play Bodak Yellow every night in your honor."