Winslow told ESPN.com Sunday night that his "unspecified illness" was a staph infection.
This is the second time Winslow was diagnosed with staph, and it's at least the sixth known case with the Browns in the past several years.
Teammates Joe Jurevicius and Braylon Edwards also are among the recent Cleveland players to contract staph while with the team.
Winslow was quiet about his previous condition for nearly two weeks until revealing it Sunday night.
"I didn't want to be a distraction and I didn't want it to steer us away from our focus, which was on the Washington Redskins,'' Winslow told ESPN.com. "Then I thought about it, and thought about it, and this is the right thing to do to get it out there and let it be known that this is not right.
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"They didn't even want me going to the Cleveland Browns' facility because they didn't want me to get re-infected. Something is wrong up there. It needs to be fixed."
Winslow spent about a week recuperating and missed the Oct. 13 game against the New York Giants. He said he was very upset with the way the team explained to the media that it was Winslow who didn't want the information public, when Winslow said it was the Browns' idea to hide his condition.
"Nobody knew that I had staph on the team because the Browns didn't want it to get out,'' Winslow said. "But it's my teammates' right to know what's going on at the facility to protect them. Their safety is at risk, too, and I didn't agree with the Cleveland Browns, because they are protecting the organization and not the players."
Winslow said he had a recent one-on-one talk with Browns general manager Phil Savage before deciding to speak with the media about the staph infection. It was the first time the two talked since Winslow was sidelined, which also was a point of discontent.
"I didn't get a 'How are you doing Kellen? It's good to have you back.' Nothing like that,'' Winslow said. "I was very disappointed. I basically told him I don't feel appreciated on this team by you, and I feel like a piece of meat sometimes."
Winslow said he plans to make a statement through his publicists Monday. He also reiterated to ESPN.com Sunday night that this is strictly a disagreement with upper management -- not anyone else -- with the way the Browns mismanaged a serious health issue.
"I love my teammates and I love my coaches, but I disagree with the front office with how they've handled this,'' Winslow said. "I'm going to play for the Cleveland Browns regardless because I love playing here. I'm not going to let anyone take the love of the game away from me. I'm going to keep playing like I've been playing, which is hard every down."
James Walker covers the NFL for ESPN.com.