NEW YORK — Robin Roberts says Friday will be her last day co-anchoring “Good Morning America” for a while.

On Monday’s edition of the ABC News wakeup program, Roberts made official the start date for what’s being called her “extended medical leave.”

Roberts told viewers in July that she has MDS, a blood and bone marrow disease once known as preleukemia.

She says she will be hospitalized next week to prepare for the bone marrow transplant that will take place about 10 days after that.