The possibility of reinstating Navy Captain Brett Crozier, who was relieved of his command after sounding the alarm about coronavirus on the USS Theodore Roosevelt, is not off the table, according to Secretary of Defense Mark Esper. He said no decision will be made until after an investigation is complete.

Crozier was removed last week after a memo he circulated pleading for help from Washington became public. More than 400 of the 4,000-person crew on the USS Theodore Roosevelt, a Navy aircraft carrier docked in Guam, have tested positive for the coronavirus so far.

Then-acting Secretary of the Navy Thomas Modly said the captain went outside the chain of command by not bringing his concerns to his direct superior. Days later, Modly resigned after a recording of him harshly criticizing Crozier became public.

"When I replaced the acting Navy secretary three days ago, I called him and the chief of naval operations into my office. I gave them some guidance. One of the things I told them is this: No further action will be taken against Captain Crozier until the investigation is completed, and once that's completed, we'll see where that takes us," Esper said on "CBS This Morning" Friday.

"So we've taken nothing off the table. What I look to do is hear from the chain of command. My inclination is always to support the chain of command and to take their recommendation seriously. We'll see how that plays out. At some point here in the coming days, they will come to me and share with me their findings and their recommendations," Esper said.

Asked if it's ever okay to break the chain of command, Esper said, "Following the chain of command and maintaining operational security is very important in the military. There are always, you know, extreme cases where going outside the chain of command makes sense. That's why we want to see where this investigation takes us."

Esper said the Navy is "taking a lot of prudent steps" to get the coronavirus outbreak on the USS Theodore Roosevelt under control and protect the health of sailors.

"Less than 10% of the crew is infected, and all but one are mild to moderate cases," he said. "The most important thing right now is to take care of our sailors, make sure they're getting the care they needed, and then get the ship back to sea so it can perform its wartime mission."

He said they have sent supplies and doctors to the ship and have gotten "thousands of the sailors off the ship and taken care of ashore."

He added that the Navy "has over 90 ships at sea right now, and none of them have any problems, no infected crews."

Esper also commented on the servicemen and women who have been deployed to New York City and elsewhere to help treat COVID-19 patients.

"Many are deployed from their own homes, their own families. They're also risking their own welfare, their own health to help their fellow Americans, so I'm very proud of them," he said.