That's something Rivera has already been doing on a regular basis.
"I've told those guys, ‘We're going to play the guy that's most ready to go,' " Rivera said. "We've got three young guys we're going to give an opportunity to that are pretty much getting equal reps as we go through practice."
While Johnson hasn't practiced since taking a vicious shot to the knee that sidelined him for most of the second half in Monday's victory over New England, Hardy sat out practice Thursday as a precaution after complaining of soreness.
That left all the reps for Addison, Alexander and Horton.
"They do certain things a little bit different, but for the most part they're all very similar in terms of their abilities," Rivera said. "If you want to see somebody that really comes off the edge and can be a really good edge rusher, it's Mario Addison. He plays with a little bit more speed. Wes Horton is a little bit more stout physically. Frank Alexander has a little bit more athleticism and a little more feel."
Addison, who joined the Panthers late last season off the Washington Redskins practice squad, has been active for every game this season in part because he plays a major role on special teams regardless of his role on defense. He made his presence felt on defense Monday even before Johnson went down, recovering a fumble in the red zone in the second quarter.
"That was my first Monday night game," Addison said. "I was very excited."
Alexander, a third-round draft pick by the Panthers in 2012, made a significant impact as the team's third defensive end as a rookie. He hasn't had as big a role so far this season, playing in just seven games.
"It's been a rocky year, but I'm feeling good," Alexander said. "Whatever the team needs me to do, I'll be there and be ready for whatever.
"I've got to take advantage of each opportunity because you never know when you'll get the next one. You've always got to be prepared and ready for anything to happen."
Alexander's limited role has been a credit to Horton, an undrafted rookie from Southern California who made the opening-day roster and has played six games.
"We've got a good group of young men, a good group of football players, and you like to believe that when you get an opportunity guys are going to step up," Rivera said. "The other thing you expect to happen is for the other 10 guys to step up as well. One guy can't do it himself, but as a collective unit they should all step up."
MIAMI MEMORIES: From 1970-2002, at least one Shula was on the Dolphins' coaching staff for all but four seasons. The run includes the 1991 and 1992 seasons, when Don Shula was head coach and his son, Panthers offensive coordinator Mike Shula, was on his staff.
"There are still some people in the organization that are special to me," Mike Shula said.
But Shula said that Sunday's game wouldn't be awkward for him, estimating that he's been in the visitors' locker room at Dolphins games eight or nine times now.
Still, he has fond memories of time spent in the home locker room.
"I was five when we moved there, so I pretty much grew up there," Shula said. "I was real young when they had the undefeated season. As I got older, I was out there in the middle of it in training camp. I charted plays on the sideline and got to travel with the team at times. Those are a lot of neat memories."
Given Shula's ties to the Miami area, a reporter asked him for a restaurant recommendation.
"Shula's, of course," Shula said.
GIVING BACK: Rivera said that the effort by him and his wife, Stephanie, to call attention to the recent typhoon that devastated the Philippines resulted in nearly $30,000 in donations from the Panthers locker room.
"We're pretty excited about that," Rivera said. "That was a heck of a response from our locker room, from our players and coaches. That was tremendous."
The Riveras both have relatives who survived the tragedy. Panthers fans can still give to the Red Cross' relief efforts by texting the word "TYPHOON" to 90999 to make a $10 donation or by visiting www.redcross.org/nfl.