ORCHARD PARK, N.Y. — A.J. Klein was a punching bag for Bills fans earlier in the season.

He was missing tackles and getting beat in coverage. 

However, something has changed over the past three games that has Klein playing the best football of his entire career.

"For me, it was finding that familiarity and just going out and playing free," Klein said Thursday.

That freedom helped Klein earn AFC Defensive Player of the Week honors on Thursday after recording a career-high 14 tackles, 1.5 sacks, 3 TFL, and 1 PBU.

Even with it being the first time he's ever won the award, the Bills linebacker downplaying things.

"Accolades are just a testament to what we've been doing as a defense, to be honest," Klein said. "I was lucky enough to be put in the position to be able to make plays, but that goes with the defensive scheme and the coaches and everybody on the defense doing their job. So everything in this league I take with a grain of salt. That's not the tip of the iceberg and personal accolades are not what we play for, not what I play for."

Exactly how Klein fit into things with the Bills defense was unknown in the beginning. 

"I think early on that was a little bit of a feeling-out process on his part and ours as well," defensive coordinator Leslie Frazier said earlier in the week. "We had an outside linebacker in Matt Milano who has been very, very productive in that role."

"We didn't know if A.J. could do some of the things that we ask Matt to do. But as we've gotten more comfortable with him and he's gotten more comfortable with our system. We've seen him play some much-improved football," Frazier added.

Improved is an understatement. Klein leads the Bills with five sacks and is fourth on the team in tackles with 58.

Most of that has come over a three-game surge where Klein's producing more than he has in any other full-season over in his career.

Klein has played 12 or more games in all of his seven previous seasons in the NFL. The most sacks he tallied in a full season was 2.5 in 2019.

Over the last three games, Klein has notched 4.5 sacks. That is nearly a third of his career total of 15.5.

Klein has 25 career QB hits.

Seven of those have come these last three games.

Klein had registered double-digit tackles twice over those seven seasons.

He has done that for the past two weeks.

That is a highly impressive hot streak, but not one that Klein believes is a product of drastic change.

"I feel like I've always played at a high level," Klein said. "I always prepare at a high level every single week, so whether or not that's reflected in the stat line or not, my mentality and my preparation hasn't changed over my entire career. It is nice to string these games together because I want to be able to contribute to the team to help the team win and that, for me, is what's most important."

​Klein has flourished filling in for Milano as he's been on IR with a pec injury. The Bills designated Milano to return to practice earlier this week, beginning the 21-day window before he must be activated to return, and also starting the clock as to when Klein's role may change.

"Depending on when he comes back, how close is he to being the Matt that we saw before that injury, that will probably determine how it'll affect A.J.'s role," Frazier said. "So even though he's coming off of reserve, will he use that shoulder? Will he be able to do some of the things that would be required at linebacker? We don't know that. And will he be as effective as he was before the injury? So some of those things we have to find out and that'll determine how it affects A.J. as well."

"I understood my role when I came here," Klein said. "I came here to help and contribute to win. Whether or not my role changes or time on the field changes that's not a concern to me. All I have to do is try to maximize the time I am on the field."

That time is not over just yet. While the Bills tried playing Milano in a limited capacity before placing him on IR, Frazier admitted that was tough for the defense as a whole with him in and out of the line-up. With that in mind, paired with Klein's rise in production, the Bills may be in a position to not bring Milano back until he's as close to fully healthy as can be this season.

"We have to be smart and we'll get a better feel once we're on the field and start practicing and just see how Matt moves around," Frazier said. "See how much he's using that shoulder. That'll probably tell us a lot about what direction to go. Even though he's still back out there, you still have to have the confidence to go out and do the things you have to do to play at a high level. We'll definitely have to be smart as a staff and our medical staff will give us direction, but we'll also be aware as he practices and gets back in the flow of things."

In the meantime, A.J. Klein will look to keep his career-best flow going in relief.