ABC says the wife of Republican presidential hopeful Mitt Romney will be on hand at the morning news program for its 8 a.m. (Eastern time) hour. Joining George Stephanopoulos at the anchor desk, Mrs. Romney will be filling in for co-anchor Robin Roberts, who is on extended medical leave.
ABC says it is in discussions with first lady Michelle Obama for a similar guest appearance when her schedule allows.
Stephen Colbert, Oprah Winfrey and the cast of "Modern Family" have previously been announced to substitute for Roberts, who had a bone marrow transplant last month.
Roberts' absence came as "Good Morning America" has overtaken NBC's "Today" show in the ratings after years in second place.