Anfernee Simons said at Media Day that he was ready to be more engaged on the defensive end. He reiterated that at training camp. However, it was his actions that spoke loudest.
From the moment Simons arrived, he has worked closely with assistant coach Ross McMains. Step one was proving his commitment, but the focus for him and the Boston Celtics is helping him grow on that end of the floor.
Simons and McMains' work together has helped deliver commendable results. The eighth-year guard has become an appreciably more impactful on-ball defender.
He is also averaging 1.1 deflections per contest, per NBA.com. Despite playing nearly nine fewer minutes, that's only a tick below what he was producing per game in his final season with the Portland Trail Blazers.
From his teammates to his head coach, the Celtics are taking notice.
What the Celtics are seeing from Anfernee Simons on defense
After shootaround at the Kaseya Center, where the C's will square off against the Miami Heat, Derrick White shared his perspective on his new teammates' development on defense.
"I think just his confidence has grown," said White. "I think a lot of times, you, I wouldn't say panic, but like, maybe reach or something, or might foul. Right now, he's just been super solid and just trusting his instincts. And so it's been cool to see someone that's dedicated to that side of the ball, and he's came in and done a lot of great things for us."
It's perhaps what has impressed Brad Stevens the most during Simons's first season in Boston.
"Defensively, I've just been really impressed, like, he's picked up, he's made it hard," said the Celtics' president of basketball operations during a December media availability at the Auerbach Center. "I think he's made great strides in the months he's been here on that end. And I'm a big fan. I like him a lot."
Joe Mazzulla, who has praised the 26-year-old guard for the sacrifice that comes with going from Portland's primary option on offense to becoming Boston's sixth man, has also commended Simons for "His ability to impact the ball, his ability to ball-pressure, he's just played well for us."
Payton Pritchard, who used to challenge himself against his new teammate when he was starring for the Oregon Ducks while the latter was early in his NBA career, always believed that Simons had it in him to play like this on defense.
Payton Pritchard on Anfernee Simons’s defense:
— Bobby Krivitsky (@BobbyKrivitsky) January 6, 2026
“I think he’s always had that ability. It’s a little bit harder when you’re the main engine to maybe play defense every night at a high level…But for him, he’s expanding his game, but he’s always been capable of this.” https://t.co/2VGNaPB3Tq pic.twitter.com/thSwCjXRG2
"I think he's always had that ability," stated Pritchard after a 115-101 win over the Chicago Bulls earlier this month. "It's a little bit harder when you're the main engine to maybe play defense every night at a high level…But for him, he's expanding his game, but he's always been capable of this."
To Pritchard's point, Simons has a six-foot-seven wingspan, and the foot speed to suggest what he's showing now was in him all along. Not shouldering the same workload on offense hasn't just made it easier for him to demonstrate that; it has made it mandatory. The sixth man, especially one on a new team, now suiting up for a franchise accustomed to winning, won't have the same leeway he would as the primary option on offense for a team that finished 10 games below .500 last season.
Simons's raising his play on defense is also occurring at an ideal time. He's scheduled to become a free agent this summer. The former first-round pick is likely in for a significant paycut from his $27.7 million salary. However, showing he's a better two-way player than previously demonstrated will help limit that reduction.
It's also bolstering his case for the Celtics to keep him, not only through the trade deadline, but perhaps re-signing him in the offseason.