Miller played 11 games for the Raiders the last two seasons. He was used most heavily on punt returns, and totaled three catches for 40 yards.
Jackson played 12 games for the Giants last year and was waived injured with a hip injury earlier this season.
St. Louis could also lean more on veteran Al Harris this week at Green Bay.
The 36-year-old Harris starred with the Packers from 2003-09. He has been playing in nickel and dime packages but was with the first string Monday as the winless Rams (0-4) returned from their bye.
"I feel awesome, life is great," Harris said. "We're all living the dream, we've just got to get some wins."
The Rams will also give cornerback Rod Hood, signed in late September and coming off reconstructive knee surgery in June, his first playing time since 2009. Hood stayed in St. Louis during the bye, and watched film with a defensive assistant and by himself.
"I just tried to get myself in the playbook as much as possible," Hood said. "It's unfortunate what happened, but it's time for some guys to step up."
Coach Steve Spagnuolo has been reluctant to give Harris too much playing time thus far. He noted that the team is running out of options after losing Fletcher and Bartel for the year.
"We want to take a look at everybody we have," Spagnuolo said. "Rod and Al are going to have to play some football, otherwise we don't have enough."
Harris would start opposite Justin King, who inherited Bartell's starting spot. King has been burned for four touchdown passes the last two games.
Information from The Associated Press contributed to this report.