After trading Marcell Dareus to the Jaguars last season, a lot of people had one question: What in the world are the Buffalo Bills doing? As it turns out, making more room for former Panthers players.

Sean McDermott and Brandon Beane have not been shy in adding former Panthers to the fold, and that is expected to continue with defensive tackle Star Lotulelei reportedly agreeing to terms on a five-year deal with Buffalo, per ESPN.

Lotulelei will be joined on the interior of McDermott's 4-3 defense by the Bills' all-time leader in sacks for a defensive tackle: Kyle Williams. Williams has played his entire 11-year career with the Bills, notching 43.5 sacks. The Bills themselves refer to him as the defense's "heart and soul," and they aren't wrong.

As for Lotulelei, the Panthers drafted him in the first round with the 14th overall pick in 2013. In that span, he has 11.5 sacks and 83 combined tackles. He's been a steady presence on the field, though some Panthers fans were disillusioned with him in his final years due to poor run stuffing percentages and analytic performance. Losing Lotulelei and Andrew Norwell may hurt the Panthers, but they'll look to retool sooner than later after making the playoffs last year.

Lotulelei had four sacks in 2016, but only 1.5 last year. Of course, as a player that is essentially a nose tackle, sacks aren't the end-all-be-all for how he influences the team. But McDermott will likely ask for a lot out of Lotulelei out of the gate, especially for a five-year deal with a player he knows. Lotulelei was mostly a space-eater for the Panthers -- Ron Rivera acknowledged as much -- but Lotulelei was 45th of 49 defensive tackles that took at least 50 percent of snaps in 2017, according to Pro Football Focus

Wherever you stand on analytics, Lotulelei will need to get better to justify that contract in Buffalo. He has the potential -- he was in the higher tiers of rankings in his first two seasons -- but the Bills are clearly betting on his drop-off not being a trend. The Bills were 29th in the league in rushing yards against last year with 124.6 per game. They need to see instant improvement on that number for this investment to be worth it.