The Raiders announced the signing of Giorgio Tavecchio, who was with the franchise as a member of the practice squad, to the active roster Saturday after placing Janikowski on IR.
According to the Raiders' official injury report, Janikowski had been a limited participant in practice this week and was listed as questionable for Week 1 with a back injury.
Janikowski has been in the news recently due to a contract dispute with the Raiders. NFL Network's Ian Rapoport reported Thursday the veteran kicker agreed to take a $1 million pay cut and accepted a $3 million fully guaranteed salary this season.
On Sept. 4, Rapoport reported the Raiders were "concerned" about Janikowski's back due to his age (39), adding he was "slow to bounce back."
Janikowski has spent his entire career with the Raiders after being drafted 17th overall in 2000. He has only missed four games in the past 17 seasons.
Tavecchio is a 27-year-old undrafted kicker out of California. He has spent time with the San Francisco 49ers, Detroit Lions and Green Bay Packers' practice squads but has yet to play in a regular-season game.
The Raiders will open the 2017 season against the Tennessee Titans with a 1 p.m. ET kickoff Sunday at Nissan Stadium.