The 49-year-old television personality and former professional football player returned to the morning show Monday after testing positive for COVID-19 in January.
Strahan's co-hosts Amy Robach and George Stephanopoulos welcomed Strahan back to the show as he was about to launch into the morning news.
"Hold on for a second, Michael. Welcome back!" Stephanopoulos said.
"Welcome back!" Robach added. "Yay, Michael's back in the house."
Strahan responded with surprise and a laugh.
"George, I gotta be honest with you. You just scared me to death. I'm like, 'Did I mess up?' Oh, man," Strahan said. "Thank you for the welcome back!"
GMA co-host Robin Roberts confirmed on the show Jan. 28 that Strahan had tested positive for COVID-19 and was quarantining at home. Strahan gave a health update while appearing on GMA from home Feb. 3.
"I just want to let you know that I do feel a lot better. I'm just thankful to be on the side of it that I am," the star said.
"I'm doing well. Just trying to rest as much as I can, trying to hydrate as much as I can, trying to get my strength back so I can get back to work as soon as possible. I miss you guys," he told his co-hosts.
Strahan encouraged people to take care of their health, wear masks and wash their hands.
"I did all those things, but it just goes to show me that it takes more than just you as an individual," he said. "Everybody has to do it so that we help out each other."
Stephanopoulos and his wife, actress Ali Wentworth, previously tested positive for COVID-19 in April.