Blackburn was perhaps the toughest decision when it came to starting because of the way rookie A.J. Klein played in his absence the past three weeks.
But in the end, Rivera went with Blackburn because he was playing well before the injury.
"A.J. will still have a role in the defense," Rivera said on Friday as he looked ahead to a showdown of the 9-3 teams. "The biggest thing to understand is when Chase left because of injury, Chase was playing well. We're putting a guy in there that has had success.
"Believe me, this was not an easy decision. It was weighed very heavily."
Rivera said while he was excited with the way his young players performed the past few weeks as fill-ins, he was "thrilled" to have key players back.
Noise factor: Rivera said heavy winds were more of a detriment to Friday's practice than the jet engines used to replicate the noise they will face in the Superdome.
"Other than that, good decisions, communication was good ... a lot of nice things that we did today, yesterday and Wednesday," Rivera said.
Kubiak reaction: Rivera was on the coaching hot seat after a 1-3 start, but it was Texans coach Gary Kubiak who became the first casualty of the season after his team lost its 11th straight game on Thursday night.
"It's the unfortunate part of it," Rivera said of Kubiak's firing. "It's a tough business. Believe me, I've been through it. He'll find work soon. He does a nice job with what they do offensively."