Kopecky, 33, entered camp hopeful for a second stint in Chicago. He racked up two goals and eight points during his second regular season with the Florida Panthers.
Visnovsky, 39, is currently an unrestricted free agent after playing the past three seasons with the New York Islanders. He scored 11 goals and added 34 assist for 31 points, including 20 points a season ago.
Both players were on tryout contracts.
Visnovsky appeared to be an option to make the team with Michal Rozsival still recovering from an ankle injury. With Rozsival not expected to start the season, Ville Pokka -- who was sent down to Rockford -- Erik Gustafsson or Viktor Svedberg could serve as the seventh defenseman.
The Hawks' active roster now includes 20 forwards, 11 defenseman and three goaltenders. They will travel to St. Louis to take on the Blues on Thursday in preseason action.