Sixers guard Ben Simmons is serious when he says he believes he's the best defender in the league. Since two seasons ago, the three-time All-Star has put an emphasis on how hard he's worked on that part of his game.

Last year, Simmons received some solid credibility as he was named First-Team All-Defense, but that wasn't enough for the young guard. This year, Simmons wants his recognition as the best player in the NBA on defense.

“I take pride in guarding the best player on the floor every night,” Simmons said last month. “It’s not a one-off thing. If you watch me, I’m typically guarding the best player, and typically the best players are guards, and I love that.

"I love that my teammates can look at me and tell me, ‘You’ve got to go out and lock this guy up.’ There are nights that guys go off. It’s going to happen. But most of the time I feel like I’m doing a good job and making the right plays. I feel like I’m the best defender in the NBA.”

According to NBA.com's latest Defensive Player of the Year rankings, Simmons has claimed that spot. Last week, Utah Jazz center and two-time DPOY Rudy Gobert had the No. 1 spot. As Simmons' dominant defense continued to shine bright last week, though, the Sixers guard dethroned Gobert for the week.

"Even when things don’t go well for the Sixers’ defense, Simmons seems to do his part. Rivers blistered the team’s transition D after its overtime loss to Cleveland last weekend, in which Cavs guards Collin Sexton and Darius Garland combined for 53 points. But when Simmons was matched up with them, they managed just eight of those, per NBA.com stats. Simmons is tied for the league lead in deflections (3.9) and loose balls recovered (1.4), and his net rating (14.0) over the past week was better than Gobert’s (11.3)."

It's only been a week with Simmons on top, but the position is well-deserved. And if Simmons can continue to play the way he's been playing, there should be no question he'll be a finalist and potential winner of the award. 

Justin Grasso covers the Philadelphia 76ers for Sports Illustrated. You can follow him for live updates on Twitter: @JGrasso_ & Instagram: @JGrassoNBA.