Miami cornerback Vontae Davis is lining up in an unfamiliar position at Dolphins' training camp -- the slot.

The cornerback and former first-round draft pick has been setting up inside at nickelback in recent practices after being pushed like never before in his career thanks to the signing of free-agent defensive back Richard Marshall.

Davis is No. 2 on the depth chart behind Marshall, opposite starting cornerback Sean Smith.

But first-year coach Joe Philbin was surprisingly supportive of Davis after the release of the depth chart on Monday, signaling the competition is far from over.

"I think [Davis] has actually practiced well the last couple of days, he made a couple of plays again today," Philbin told the Miami Herald. "But there's good competition there. That's a good thing right now. It's early, but I don't anybody should be concerned. The whole ball club needs to show a lot of improvement and he's no different right now."

But whether it’s Davis or Marshall starting, the secondary needs to improve after an abysmal 2011. The passing defense ranked No. 25 in the league as it allowed 250 yards per game and 24 passing touchdowns last season.

Making his case: Jeron Mastrud sure hasn’t looked like a player with only one career NFL catch.

The third-year tight end has been one of the biggest surprises of training camps, using his 6-foot-6, 262-pound frame to earn time with the first-team. His blocking is a huge plus for a team with an unsettled quarterback situation that is expected to rely heavily on the run.

But who will Miami cut? The team is likely to only keep three tight ends.

Starter Anthony Fasano is the clear No. 1 and had two touchdown catches in last weekend’s scrimmage. The team used a third-round draft on Michael Egnew and the front office is enamored with the receiving talent of Charles Clay, but neither is considered even an average blocker.

Mastrud literally may muscle his way onto the 53-man roster.

Don’t touch that dial: In just a few hours we will find out if anyone on the Dolphins is Emmy worthy.

The team debuts on HBO’s hit NFL training camp series “Hard Knocks” on Tuesday night at 10 p.m. ET. The program is famous for its raw look at the life of professional football players and coaches and the process that goes into building a team.

Check out the most recent trailer here.

For more up-to-the-minute news and analysis on the Miami Dolphins from blogger Dave Carey, follow @CBSSportsNFLMIA.