ABC News announced Tuesday that Michael Strahan is leaving "Live! With Kelly and Michael" and joining "Good Morning America" full-time.

TMZ reported that Strahan's cohost Kelly Ripa and "Live!" executive producer Michael Gelman were blindsided by Strahan’s departure, and that Strahan only told them on Monday after their show, leaving Ripa "stunned and upset."

Ripa was a no-show for the Wednesday morning show and actress Ana Gasteyer co-hosted with Strahan instead. According to the gossip site, Ripa feels disrespected and may not show up for "Live!" for the foreseeable future.

So why the sudden change? Just two months ago, Strahan raved about his co-host and the show, plus he was already working part-time on "GMA."

In February, Strahan gushed about Kelly and "Live!" to FOX411 showing no signs of quitting the show anytime soon.

"Kelly is fun," he said. "It doesn't feel like work. Every day we laugh together. Literally, she is my work wife. I am married at work, and I am married to a fun woman, who comes in every day and brings her A-game."

TMZ said Disney CEO Bob Iger orchestrated Strahan's move to "GMA" to help shore up the show's sagging ratings.

In 2012, “GMA” defeated “Today” for the first time in 16 years, but has since since seen a marked drop. “GMA” saw a 7 percent viewership drop for the week of April 8th with a 19 percent drop in the 25-54 age audience, while “Today” only saw a 2 percent drop. “CBS This Morning” gained viewers over the same time period.

Strahan replaced Regis Philbin on "Live!" in 2012 and ratings went up. In May 2015, “Live” posted their best May sweep performance since 2007, growing 4 percent in homes and 6 percent  in total viewership.

Pop culture expert Cate Meighan says the move makes sense for Strahan.

“After spending four years on 'Live' he may just be excited at the idea of being able to tell a different kind of story,” she said. “My guess is that the dollar signs that go with his new full time position at ‘GMA’ only sweetened the deal. If you look at Strahan's career in broadcasting he likes to keep moving and challenging himself, this may simply be another example of that.”

Fans took to social media to express confusion in Strahan’s departure.

The former football star released a statement to The Hollywood Reporter looking forward to his new chapter and thanking Ripa. 

"I look forward to continuing to work with the incredible team at GMA. It is an exciting opportunity to be able to bring unique stories and voices to the audience," Strahan said. "My time with ‘Live With Kelly and Michael’ has been transformative, and my departure will be bittersweet. Kelly has been an unbelievable partner, and I am so thankful to her and the entire team. I am extremely grateful for the amazing support I've received from all of the fans.” 

Strahan will continue to host “NFL Live” for Fox Sports' National Football League coverage on Sundays as. 

Strahan starts on “GMA” on September 19th with co-hosts George Stephanopoulos, Robin Roberts and Lara Spencer. 

ABC, Ripa and Strahan did not return FOX411's request for comment.

You can follow Blanche Johnson on Twitter @blancheFOXLA.