According to Daniel Brown of the Mercury News, the 32-year-old admitted that the itch to play creeps up at times but isn't strong enough to pull him back in: "That inclination [to play] only comes for a split second. And then it's, 'Nope, nope, I'm cool.'"
Willis was a significant part of the Niners' trips to three consecutive NFC Championship Games in the 2011, 2012 and 2013 seasons.
He retired after San Francisco went 8-8 in 2014, and the team is just 7-25 since then.
Willis encouraged the current 49ers players to hang in there like he did during the team's struggles early in his career, and he also revealed that he's pulling for them to succeed: "When I came in, we weren't very good, either. We'd get beat up. So to see where they are now? It's like, 'This is all part of what happens, you guys.' I wish those guys all the best. Just fight the good fight."
Since his retirement, the seven-time Pro Bowler has become a big fan of mixed martial arts and even does some MMA training on occasion.
When asked if there could be an MMA career in his future, though, Willis suggested he was happy on the outside looking in: "I can't sit here and fabricate and make it sound like that at all. I'm just a fan of fighting."
While the 49ers have lost a ton of talent from their defense in recent years, Willis was undoubtedly the biggest departure, and it has had a hugely adverse impact on that side of the ball.
San Francisco ranked last in the NFL during the 2016 campaign in both total yardage and points allowed.