On Sunday, his actions spoke far more loudly than his words. Jackson, a first-round pick by the Texans in 2010, starred as he and the Broncos rolled to a 38-24 victory over the Houston Texans.
"He kind of put us in that spirit of that 2015 playoff run," Broncos linebacker Von Miller said. "I said it [Saturday] night, let's do it for KJ. ... We did that for KJ."
Jackson, who left the Texans in free agency last March without a contract offer, finished with a 70-yard fumble return for a touchdown, an interception, 11 tackles, three passes defensed and one attention-grabbing hit on Texans All-Pro wide receiver DeAndre Hopkins to break up a pass.
"I think you could say he had a hell of game," Broncos coach Vic Fangio said.
"Very emotional, especially once I kind of got here, got off the bus and starting seeing familiar faces," Jackson said. "Been here for nine years and develop a relationship with pretty much everyone in the building. ... I was excited to see everybody, but at the same time [I] had to keep my mind that it was a business trip."
Jackson was all business right from his first tackle, when he stopped Texans running back Carlos Hyde for a 2-yard gain 2½ minutes into the game. He then turned momentum squarely in the Broncos' favor.
On a first-and-10 play for the Texans from the Broncos' 37-yard line with 3:52 remaining in the first quarter, Houston quarterback Deshaun Watson completed a 9-yard pass to wide receiver Keke Coutee. Coutee was hit by Broncos linebacker Alexander Johnson, knocking the ball free.
The fumble was scooped up by Denver linebacker Jeremiah Attaochu and Attaochu, who was in the grasp of a Texans player, handed the ball to Jackson, who sprinted up the Broncos' sideline 70 yards for the score. Several Houston players looked somewhat surprised that officials had allowed the play to proceed. But the fumble and return were reviewed and upheld, giving the Broncos a 14-0 lead.
"I saw something grab [Attaochu], thought he was tackled and I could kind of see everybody relax," Jackson said. "It was one of those plays they didn't really know if it was an incomplete pass or a fumble. ... I never heard the whistle, it was great awareness by Jerry to recover the ball. I was right there, he heard me."
Jackson continued to get the Texans' attention the rest of the way. His massive hit on Hopkins not only knocked the ball free, but also came on third down to end a Houston possession. He later stopped tight end Darren Fells for no gain on a third-and-1 to end another Texans possession.
After opening the season as the Broncos' nickel cornerback because of injuries elsewhere, Jackson moved back to safety and has helped Denver maintain some consistency even as injuries have chipped away at the team's pass rush.
The Broncos led 38-3 midway through Sunday's third quarter, an impressive effort on the road against a Houston team that had defeated the New England Patriots the week before.
"I've gotten comments from a lot of people around the league and I have a couple really good friends on this [Texans] staff here, guys that wouldn't B.S. me," Fangio said. "They really are impressed with how hard our guys played. The energy, the intensity, and you know, it's not a bunch of B.S., these guys have played their asses off all year from an effort standpoint, focus, try-hard and [I'm] really happy to see them get rewarded."