Watson threw briefly on the field Sunday during pregame in front of Browns officials before the decision was made to make him inactive.
Browns coach Kevin Stefanski said after the game that he expects Watson to return for Cleveland's next game in two weeks against the San Francisco 49ers. The Browns have a bye next weekend. Stefanski added that Watson has no structural damage or torn ligaments in the shoulder.
"Obviously, he did not feel comfortable to be the player we needed him to be to play," Stefanski said. "He's very disappointed, he wanted to go badly. But he just did not feel that he could go."
Stefanski had said on Friday that he was "hopeful" that Watson would be able to play. But after trying to warm up during pregame, Watson decided that he wouldn't be able to go.
"He was hopeful that he would feel good today. He didn't," Stefanski said. "He knows his body. I trust him. He just didn't feel like he could operate at enough of a level to play."
Without Watson, the Browns offense struggled against the Ravens. Cleveland's only points, a field goal, came after a 37-yard defensive pass interference call. Rookie Dorian Thompson-Robinson started in place of Watson and completed just 19 of 36 passes for 121 yards. He also threw three interceptions.