"I've got to freshen this team up," Mariucci said Wednesday afternoon.
Coming off a draining 23-20 overtime victory against the Raiders, the 49ers must prepare this week for a Kansas City Chiefs team that is fresh off its bye week. And we're talking really fresh. The Chiefs didn't have one player listed on their injury report Wednesday.
"And ours is full up," Mariucci said. "So I wanted (his team) to have two days to let everything calm down, two days to recover physically and emotionally before we crank it back up. Now, we've got a lot of injured guys in that training room that didn't practice at all. So I have to freshen the team up, so shortening practice down is part of the plan."
The Niners combined their normal Wednesday morning walkthrough and afternoon practice into one session, something they never did last year on a Wednesday, which typically is the day they get the most work in preparation for their next opponent.
Several of San Francisco's starters didn't participate in drills. Star receiver Terrell Owens, Pro Bowl center Jeremy Newberry, left tackle Derrick Deese, tight end Eric Johnson, strong safety Tony Parrish and kick returner Jimmy Williams each were held out of practice. Williams and Deese aren't even among the seven players listed on the team's injury report.
Even with the condensed practice, Mariucci eliminated certain drills and took a couple plays out of each team period. "We simply needed to change it today," he said.
The Niners also made a personnel change, elevating safety John Keith from the practice squad to the 53-man roster. Keith immediately moves in as the backup safety to Parrish and starting free safety Ronnie Heard. Keith takes the roster spot of Jason Moore, who was released Tuesday.
While the Niners are trying to get fresh as a team, Keith already is there. He hasn't played since tearing ligaments in his left knee during the opening kickoff of the season opener against Atlanta last season.
"I'm ready to go," said Keith, the Niners' fourth-round draft pick in 2000 who started three games that year before a broken arm ended his rookie season in Week 6. "I've been ready to go."