Neither player has practiced all week and both are listed as doubtful on the injury report.
"He was working on the side today," Rivera said. "We'll see how he reacts tomorrow morning. You've got to really test it and find out on Sunday."
Rivera said defensive tackle
"His big thing obviously will be getting back into football shape," Rivera said. "The conditioning part, you can never really simulate that, and that will be the hard thing for him. We want to make sure we take advantage of this week and get him ready."
After a three practices following a difficult defeat in Atlanta, Rivera was pleased with how his team's sessions improved throughout the week. He's hoping to see that carry over into their Week 5 performance.
"Practice today had a good tempo. It was upbeat, it was energetic," Rivera said. "Each day got better and better. Wednesday was the toughest day, but today was one of those days you felt really positive about. It's something you can build on and, hopefully, take into Sunday."