Kinumbe, a 19-year-old defender from Montreal who signed an MLS contract with the Impact last November, spent half of the 2018 season with the Fury in the United Soccer League.
The 31-year-old De Freitas is a Brazilian/Italian midfielder who has played for clubs in Italy, Germany, Portugal, Hungary and Greece as well as FC Edmonton in the NASL.
Samb, a 25-year-old forward, has played in his native Senegal, France and most recently with Norway’s Tromso.
“We’re pleased to add these three players to our roster and we look forward to seeing where they can take us,” Ottawa GM Julian de Guzman said in a statement.
The signings bring Ottawa’s roster to 19. The club kicks off its 2019 USL Championship season on March 9 at the Charleston Battery.