It's a major loss for South Carolina. Samuel had six touchdowns in the team's first three games, including a 68-yard receiving score on the opening play against the Wildcats.
But Samuel was slow to get up after a 9-yard catch in the third quarter Saturday. He was taken into the medical tent and returned to the field shortly after. His return did not last long, however, and he walked into the locker room, finishing the night with five catches for 122 yards and one score.
Gamecocks coach Will Muschamp announced the extent of the injury after the loss, South Carolina's first this season.
"I believe it's his fibia. I don't have all the information, but I know he's going to be out for the year," Muschamp said. "Disappointed for him. He's a wonderful young man. He came off the field and tried to go again."
Samuel had opened the season on a tear, with two touchdown receptions, two kick returns for a score and a rushing TD entering Saturday.
South Carolina has lost four straight to Kentucky and will face Texas A&M and Tennessee in road contests in the next four weeks.
"He's an outstanding teammate and an outstanding friend," quarterback Jake Bentley said. "He's going to be hard to replace."
Information from the Associated Press was used in reporting.