Detroit general manager Martin Mayhew first told the team's official reporter and MLive.com about the surgeries.
Johnson dealt with injuries all season, from a pair of knee injuries that kept him out of two separate games and at least one practice per week, to the finger that Mayhew said was not pointing straight.
"He played the entire season where the finger was really pointing perpendicular from his body," Mayhew told MLive.com on Wednesday. "He's trying to catch the ball [awkwardly]. He would never complain about that, but that was certainly a factor I think in the way he played."
He had a career-high nine drops this season.
The 28-year-old still managed to catch 84 passes for 1,492 yards and 12 touchdowns this season. His yardage was fourth in the NFL and he was 17th in receptions. In 14 games, he came 8 yards shy of being the first receiver to have three straight 1,500-yard seasons. He has now compiled four straight 1,000-yard seasons.
In his career, Johnson has 572 receptions for 9,328 yards and 67 touchdowns.
Johnson also pulled out of next week's Pro Bowl due to the injuries.