The Vikings said Joseph was an innocent bystander at the time of the incident, which occurred inside 400 Soundbar just before closing time. The team described Joseph's injury as minor and that he was treated at a hospital and released Saturday.
Joseph, who was with other Vikings players, will rejoin the team on Sunday and isn't expected to miss more than two weeks, a source told ESPN.
According to the Star Tribune of Minneapolis, the gunman injured nine people.
"The entire Vikings organization is extremely thankful that Linval was not seriously hurt, and our thoughts are with all of the victims of this shooting," the team said in a statement. "The team will defer any further comment to the Minneapolis Police Department during its ongoing investigation."
Two people with serious injuries were in stable condition Saturday and expected to survive, police spokesman Scott Seroka said. He didn't know the exact condition of the other seven but described most as having minor injuries.
Police are still looking for the shooter. Seroka expected more information to be released Monday.
Club owner Johann Sfaellos told the Star Tribune it was a typical night with patrons busy socializing and dancing, with no fights until he heard gunshots.
"Suddenly, a person just pop, pop, pop," he said of the shooter, who he said dropped the gun on the ground and disappeared before security officers found the gun. "The whole thing was surreal. It was out of the blue."
The Vikings played a preseason home game Friday night, beating Oakland 10-6 at TCF Bank Stadium. Joseph, who is expected to start for the team at nose tackle, played nine snaps with the Vikings' first-team defense.
He signed a five-year, $31.25 million deal with the team in March, getting $12 million guaranteed to help shore up a porous Vikings run defense that had slipped since the team parted ways with Pro Bowl nose tackle Pat Williams after the 2010 season. Joseph played the first four seasons of his career with the New York Giants, starting 46 of 48 games and averaging 55 tackles and three sacks over the last three years. He was also part of the 2011 Super Bowl championship team.
ESPN.com Vikings reporter Ben Goessling and The Associated Press contributed to this report.