I think saying they are 'key players to the Dolphins winning this season' is more dependence on rookies than the team actually has or wants. Whatever good they contribute is gravy but Needing them to be key means you better sign experienced back up plans just in case. They are rookies.
Rookies come into the league and are relied upon to play well during their first season ALL The Time.
I'm sure the Jets are staking a lot on their rookie QB if they hope to have a good season.
I'm sure the Pats are looking for a lot from Darius Butler and Chung to solidify their secondary. The same goes for Sebastian Vollmer the O-lineman they drafted who's already on the cusp of getting a starting spot on their line.
I'm sure the Bills are looking for a lot from rookies Levitre and Eric Wood to solidify their offensive line THIS YEAR.. In fact, they are penciled in to start.
If you want to talk about corners, since we drafted two in the first two rounds this year--- A couple of years ago 2nd rounder Brandon Flowers started as a rookie for the Chiefs and started in all 16 games , and played very well.. Same for Darelle Revis of the Jets, Cromartie of the Chargers, and many more examples- those are just off the top of my head.
After the Colts won the super bowl their pro bowl LT retired.. They relied on 2nd round rookie Tony Ugoh from game one to solidify that LT spot.. He was picked two spots after John Beck in the 2nd round... So good teams do it all the time. As a matter of fact the Colts start rookies right away pretty often.. And they consistently have the highest amount of their own draftees on the roster in the league... The Chargers love what they see in Larry English and he will start right away.
And all through the league I am hearing the same from teams in regards to some of their rookies. That they will play in year one, and play a lot.... I only named a couple of many.
On our team, Langford and Long started from day one last year. And we had a 3rd rookie start for us in the very first game of the season, Donald Thomas... And later on in the season other rookies made their mark felt- Davone Bess, Phillip Merling, Dan Carpenter.
Most teams rely on rookies one way or another...
I think the fact that the Dolphins have had horrible drafts during this decade (before last year), makes you feel that rookies should take a long time to develop.. Well that isn't the case for most other teams.. It's just that the dolphins had horrible drafts and that's why they sucked, while the other teams who drafted better were better teams because of it. They had more rookies make an impact early on to make them better and more talented overall.