ORCHARD PARK, N.Y. -- Mario Williams' frustration with the Buffalo Bills' defensive scheme last season was one of the worst kept secrets in football.

Coach Rex Ryan was often diplomatic with how he responded to the grumblings of the Bills' $100-million pass-rusher, but once the Bills made their long-anticipated decision to release Williams in March, the gloves came off.

"With some of the comments [he made], do I wish him well? Not really," Ryan told TheMMQB.com in May.

Ryan has also taken other thinly veiled shots at Williams since he was sent packing from Buffalo.

Ryan said in March that Williams got "everything he wants" in signing with the Dolphins, who were expected to use him more in their pass rush and less in coverage. Last week, Ryan seemingly made another reference to Williams' complaints when the Bills' coach was praising the performance of Lorenzo Alexander, the NFL's sacks leader entering Week 7.

"I don’t recall him ever bitching about dropping," Ryan said of Alexander, who has eight sacks as Williams' replacement in the starting lineup this season.

Williams will play Sunday against his former team for the first time. Here are six players to watch in the game, courtesy of ESPN Dolphins reporter James Walker:

OFFENSE

RB Jay Ajayi: A lot of attention will be on Ajayi to see what he has in store for an encore. He became the first player in the NFL this season to rush for 200-plus yards in last week’s win against the Steelers. The 2015 fifth-round pick showed good burst and the ability to make long runs. Miami’s offense looks a lot better when Ajayi keeps it balanced and has it going. The Dolphins will feed Ajayi early and often Sunday in hopes he takes pressure off the passing game.

QB Ryan Tannehill: No team has given Miami’s starting quarterback more trouble than Buffalo. Tannehill is just 1-5 against the Bills in his past six starts and 2-6 against them overall. It also doesn’t help that Tannehill is off to a slow start and still trying to find his way in a new offense. He has more interceptions (seven) than touchdowns (six). Tannehill failed to commit a turnover for the first time since Week 1 this past Sunday. He was efficient and provided a blueprint for how the Dolphins want him to play. The key is for Tannehill to manage the game and not lose it.

G Laremy Tunsil: Miami’s offensive line was at full strength last week, and it showed. With the return of Tunsil, who missed Week 5 after falling in the shower and injuring his ankle, the Dolphins produced 222 rushing yards and held the Steelers to zero sacks. The rookie is coming along well and learning how to play the guard position. He was a left tackle in college, and that will probably be his future position. But his spot on the line along with left tackle Branden Albert has been a strength for Miami when both are healthy.

DEFENSE

Dolphins defensive end Mario Williams, benched for lack of production, faces nemesis Rex Ryan and the Bills in Week 7. AP Photo/Joel Auerbach

DE Williams: Remember him? Williams should be motivated to face his former team this week. Ironically, some of the same effort complaints Williams had in Buffalo have popped up in Miami during the first six games. Williams was benched last week after not registering a stat in 53 snaps against the Titans. Coaches want Williams to "play harder," particular against the run. But Williams said his effort is there and he just has to play faster. Expect Williams to play fast against a team that released him this year.

MLB Kiko Alonso: The former Bills second-round pick is another familiar face in this rivalry game. Alonso was on his way to becoming a star in Buffalo before an offseason knee injury derailed his second season. The Bills traded Alonso the following year to acquire running back LeSean McCoy from Philadelphia. Buffalo obviously won that transaction. Alonso hasn’t been the same player from his rookie year, but he has shown flashes. He leads the Dolphins with 55 tackles.

S Michael Thomas: The backup safety makes this list because of the major shoulder injury to Pro Bowl starter Reshad Jones. Miami is seeking a second opinion after it was discovered Monday that Jones tore his rotator cuff, putting his season in doubt. Jones wants to play through it, but it’s likely that Thomas will take over for Jones Sunday and potentially for the rest of the season. Thomas is a smart player, but losing Jones is a major blow. He’s one of the few game-changers on the team.