Amendola rode a stationary bicycle during Tuesday's workout and coach Steve Spagnuolo said the diminutive receiver was set to undergo tests for concussion-related symptoms on Wednesday.
"He still has some symptoms, so they weren't going to take any chances," Spagnuolo said.
Bell also had a concussion in the preseason that forced him to miss a few weeks, but Spagnuolo anticipated that the lineman would practice on Wednesday.
The 5-11, 186-pound Amendola was leveled by the Lions' Zach Follett early in the fourth quarter Sunday and didn't return to the Rams' 17-10 victory. He didn't remember leaving the field, but said he'd "probably" be on the field for the Rams' final practice Wednesday before players disperse for their off week.
Amendola is averaging 24 yards on kickoff returns and 8.5 yards on punt returns, and has 15 receptions for 128 yards.
"The hit didn't hurt, but my mind wasn't working," Amendola said. "I walked off, I think. Just got my head buzzed a little bit."
"He cleared it within two days so that's a good thing," Spagnuolo said. "Usually if it takes a little bit longer, then you get a concern."
Guard Richie Incognito, who missed the Lions game with a foot injury, is scheduled to shed a walking boot on Monday.