Watson told ABC News "Good Morning America" co-anchor Michael Strahan today that the protest by Ravens players was "organic."
"When we got on the field, some guys kneeled, some guys decided to kneel that didn't before," he said. "Some guys locked arms."
"I locked arms," he said.
Trump at a rally Friday night in Huntsville, Alabama, said teams should fire players who kneel during the anthem.
Watson said Trump's words "cut deep" for the Ravens.
"We felt as many others did that this was a direct attack on our brotherhood," he told Strahan.
Watson said he hadn't previously agreed with Kaepernick's decision to take a knee during the national anthem, but he said the president's remarks suggested players don't have the right to speak out on important issues.
"There was a tremendous amount of emotion and a tremendous amount of hurt" over Trump's words, Watson said. "Obviously, the name-calling is something we don't [stand] for but even to imply that we don't have the right to express ourselves in that way is something that we really took to heart."
Watson added that he has long been concerned about the same issues that prompted Kaepernick's protest.
"I haven't kneeled, but the reasons [Kaepernick] decided to kneel -- the police brutality the excessive force, as he said, the impression of different people of color -- those are all concerns of mine since even before he decided to kneel... my feelings have not changed about those issues."