Shelby has played 127 snaps, spelling everyone on the defensive line the past four games, and that includes the 6-foot-2, 282 pounder taking snaps at defensive tackle. With Starks sidelined he's split the defensive tackle workload with rookie Anthony Johnson, and he played in a season-high 38 snaps against the Raiders.
The Dolphins consider Shelby the sixth man of the defensive line, which usually rotates the ends and tackles to keep the starters fresh in the fourth quarter.
"He's a smart football player," coach Joe Philbin said. "He's good fundamentally. He understands the techniques that we want to use. He practices them. He transfers them to the game on a consistent basis. He's got some flexibility, position flexibility. I don't know if we want to play him inside 50 plays a game necessarily, but he certainly can function in there."
Shelby's play was so steady he worked ahead of Dion Jordan, the team's 2013 first-round pick, in the defensive end rotation last season. And even when Jordan wasn't suspended Shelby, who has six tackles, two sacks, three quarterback hurries and recovered one fumble in Miami's first four games, has a higher standing in his unit because he's a more fundamentally sound player.
And that spot is one Shelby doesn't intend to relinquish when Jordan returns at the end of the month from his six-game suspension the NFL imposed on him for failing multiple drug test.
Numbers wise, you're only allowed to bring so many people to the game and Derrick is a versatile guy," defensive coordinator Kevin Coyle said. "He gives us a guy that can rush the passer inside, he can play defensive end in the base packages. ... He is a very valuable player on our defense because he's very intelligent, he's got versatility. And when he plays he generally wins a lot more than he loses."
That's what the Dolphins hope Shelby can continue to do during his NFL career, which appears to be blossoming as the opportunities come for this former first-team All Pac-12 player, who started 40 games for the Utes.
"I'm just trying to do my part. At the end of the day if you're drafted, undrafted, that only really counts if you're just a guy. Everybody from all aspects of the team comes from different rounds, and some of the best player weren't drafted. You just have to be reliable," said Shelby, who worked his way back from a knee injury during OTAs. "I've proven that I can make plays when I'm out there. I don't want people to say I'm just a guy."