Safety Anthony Newman, who has started the last 46 games, will take a seat Sunday so the Rams can watch rookie Toby Wright.
"I've been struggling the past three or four games," Newman said. "If I'm going to hurt the team I shouldn't be out there. I've been pressing, and I haven't been taking care of business.
"It's a good wake-up call, and to be honest, it takes some pressure off my back. . . . It's a demotion, but I can rest my mind."
Coach Chuck Knox said Monday the team would play its best players in an attempt to win the last two games rather than experiment and play young players like Wright, quarterback Tommy Maddox and defensive end Brad Ottis.
But when Newman, the team's defensive captain, reported for work Wednesday he learned he was out of the lineup.
"It was a shock," he said. "But write this down: I will be back. If not here, somewhere, and if not now, then later. But I'll be back."
The Rams will use Wright at strong safety and move Marquez Pope to free safety on early downs. They will bring in rookie safety Keith Lyle on passing downs.
Steve Israel worked at the corner for Darryl Henley, who is listed as probable because of a groin injury. Ottis, the team's rookie defensive end, also earned significant practice time because of injuries to Gerald Robinson (neck) and Jimmie Jones (ankle).
Tackle Jackie Slater, who is wrapping up season No. 19, is close to deciding his future. Slater, sidelined with an elbow injury, indicated before the season that he would like to play 20 years.
"He hasn't said this is his last year," Knox said. "I think he probably could play another year; he played well when he was healthy."
Pro Bowl selections will be announced today, and while linebacker Shane Conlan is probably the most deserving Ram, he doesn't expect to hear his name called.
"It would be a nice honor, but I don't anticipate it happening," Conlan said. "It's tough when you have a team struggling like we are."
Conlan leads the team in tackles despite coming out of the game in certain passing situations, and by his own assessment, he considers this one of his most productive seasons.
"One year I was hurt and played in only seven games and I went; I was kind of embarrassed almost," said Conlan, who was voted into three consecutive Pro Bowls while playing with the Buffalo Bills.
Running back Jerome Bettis earned an invite to the Pro Bowl last year as a rookie, but at best he figures to finish third in the voting this year behind Emmitt Smith and Barry Sanders.
"I haven't done a whole lot as far as stats go," said Bettis, who ranks fourth in the NFC in rushing with 970 yards.
The Rams added linebacker Brett Collins, who was with the team earlier this season, to their 53-man roster because of injuries to linebackers Tom Homco (foot) and Chris Martin (calf).
The Rams made room for Collins by placing rookie tackle Ronald Edwards on injured reserve with bone spurs in his ankle. Knox said Edwards suffered the injury in training camp.