Kelly Ripa didn't find out her "Live with Kelly and Michael!" co-host would be leaving her for a full-time position on "Good Morning America" until after their show Tuesday -- the same day ABC sent out an internal memo with the information, TMZ reported.
The celebrity news and gossip outlet said Strahan met with Ripa and "Live!" executive producer Michael Gelman at 10:30 a.m. to let them know he was leaving the show for "GMA."
TMZ said Ripa was "stunned and upset" by the news. E! reported sources as saying she was "livid."
The unnamed E! source said the move was a network decision and Ripa was kept in the dark to prevent a leak about the information to media.
According to People magazine,Ripa told producers Tuesday night that she wouldn’t be coming in for Wednesday’s show.
Wednesday, actress Ana Gasteyer filled in as a guest co-host in place of Ripa.
"I really want to thank, of course, Kelly Ripa, because Kelly welcomed me here and I've learned so much from her, and she's just been an amazing influence on me," Strahan said at the end of Wednesday's show. "This has truly changed my life to be here with her, and I know that the show will continue to be strong and great because of Kelly. Kelly, I thank you. I love you and everyone else here at 'Live!'"
"I know that the show will continue to be strong and great because of Kelly and the staff here because everybody here is so talented," he added. "This show has not been around for over 30 years by mistake."
Michael Strahan gives heartfelt speech about leaving LIVE with Kelly and Michael: "I can't ask for better fans." http://abcn.ws/1WdYmbq
Strahan will appear on "GMA" full time starting in September.
"I'm always here," he said Wednesday on "Live!" "I'm always available to guest co-host if I get a call because I consider myself to be a part of this family forever. (But for now,) I'm not going anywhere. We still got months to go."
This is the second time Ripa found out short-notice that she would be losing a co-host.
When Regis Philbin left "Live With Regis & Kelly" in January 2011, he didn’t break the news to Ripa until moments before they went live.
Strahan joined Kelly Ripa on "Live with Kelly" in 2012, after producers searched for 10 months to find someone to replace Philbin. Ripa and Strahan won an Emmy last year for outstanding entertainment talk show hosts.
It's unclear who will replace Strahan in the fall.