Through two games, the Dolphins are tied for the NFL lead in sacks — Miami, Buffalo, Oakland and Tampa Bay all have nine each.

For Miami, the usual suspect, All-Pro end Cameron Wake, leads the way with 2 1/2.

And it’s no surprise that veteran tackle Randy Starks has two. But tied with him isn’t starting end Olivier Vernon or rookie end Dion Jordan, the No. 3 overall draft pick.

It’s Derrick Shelby, who made the roster as an undrafted rookie last year and is emerging as a key contributor.

Shelby has a sack in each of the first two games, and the advanced statistics compiled by Pro Football Focus grade him as the 24th-best defensive end out of 50 in a 4-3 scheme.

Wake is No. 5, and Vernon is last at No. 50. Jordan doesn’t have enough snaps to be graded.

Shelby (6-foot-2, 280 pounds) rates especially high in pass rushing at No. 11. His only negative grade is in pass coverage, where he is No. 48.

“He’s very technically sound, a very good fundamental football player,” coach Joe Philbin said. “He keeps his shoulders square. He has his hands where they are supposed to be. He’s smart and instinctive. He’s done a really nice job.”

Shelby had a strong preseason, but Jordan was expected to take his role as the first defensive end off the bench. In the season opener against Cleveland, Jordan appeared in 22 percent of Miami’s defensive plays while Shelby appeared in 25 percent.

In Week 2 against Indianapolis, Jordan appeared in just 10 percent of the defensive plays and Shelby 22 percent.

Jordan has instead become a fixture on special teams, playing 60 percent of the special-team snaps. Shelby has played 35 percent of the special-team snaps.

Shelby said he felt he contributed as a rookie but “this year I’ve made a couple of more plays.”

“Hopefully I can get out there a little bit more,” he said. “I can only do what I’m asked to and go out and spell Cam and OV when they need it.”

After trying to pressure Andrew Luck on Sunday, Shelby will face Matt Ryan, Drew Brees and Joe Flacco the next three weeks. Shelby, who played college ball at Utah, said he is more comfortable this season than he was as a rookie unaccustomed to high-profile opponents.

“Last year I kind of felt like I was getting awestruck half the time,” he said. “These are guys you watch growing up and now you’re playing against them. Second year, I just go out there.”

Wake said that Shelby’s emergence is no surprise to his teammates.

“I’ve noticed from the moment he got here, he’s the kind of guy that gets on the field and makes plays, the kind of guy you want on your team, who’s behind the scenes and works hard,” Wake said. “He probably doesn’t get as much credit as some of the other guys in that room.”

Vernon, however, has been a disappointment in his two games as a starter. As a rookie third-round pick last year, Vernon backed up Wake and Jared Odrick. This year, the team moved Odrick to defensive tackle.

Vernon is by far the lowest-graded 4-3 defensive end in the league. He is second-to-last in pass rushing and last by a wide margin in run defense.

When asked about Vernon’s struggles, Philbin said, “I don’t see the same things. He’s playing hard. He’s playing sound. I think he’s improving. I see some good things.

“Obviously we anticipate there will be more production as the season goes on. We think he’s giving us a good effort and has played well.”

Vernon so far this season has only an assisted tackle, on which he was credited with half a sack. He said playing the run is an area in which he could improve but said he thought he has been “pretty solid” in Weeks 1 and 2.

“It might not show in the stat sheet. I’ve just got to keep working on it,” Vernon said. “We have 14 games left. It’s a long season. I’m not worried about anything.”