"I regret that we weren't the ones back then," he said, per Jennifer Lee Chan of NBC Sports Bay Area.
The Seahawks coach also said Kaepernick kneeling during the national anthem as a means of protesting police brutality and racial injustice was not an issue when the team discussed potentially adding him in the past, per Joe Fann of NBC Sports Northwest.
That is notable because ESPN's Adam Schefter reported in April 2018 that the Seahawks postponed a scheduled workout with the quarterback because he declined to stop kneeling during the anthem if he was signed.
However, Ian Rapoport of NFL Network reported the workout was not called off solely because of the kneeling but instead because there "was not a firm plan" on how to move forward.
Carroll's latest comments come after Seahawks running back Carlos Hyde suggested making sure Kaepernick is back in the league is an ideal starting place for the NFL if the league truly wants to address racism.
"What can the NFL do? I think the NFL can start by signing Kap back," Hyde told reporters. "I think if they sign Kap back that'll show that they're really trying to move in a different direction because Kap was making a statement four years ago about what's going on in today's world and the NFL didn't bother to listen to him then. So I think they should start by doing that."
Seattle has plenty of experience playing against Kaepernick seeing how he suited up for the NFC West rival 49ers from 2011 through 2016 and led San Francisco to the Super Bowl and NFC Championship Game in back-to-back years during the 2012 and 2013 seasons.
Despite that resume and a 16-to-4 touchdown-to-interception ratio during the 2016 season, Kaepernick has remained unsigned since he opted out of his contract in March 2017.