MIAMI (CBSMiami) – Coming into the 2012 regular season, the Miami Dolphins secondary was supposed to be one of the strengths of the team. But after trading veteran Vontae Davis to the Indianapolis Colts, a position of strength has turned into a possible weakness.

The Dolphins will start Sean Smith and Richard Marshall at the two cornerback positions and will bring in Nolan Carroll on passing downs. Past that, the Dolphins don’t have much on the depth chart that will make any quarterbacks or defensive coordinators think twice.

READ MORE: ‘I Know What That Pain Feels Like’: Parkland Parents Heartbroken After School Shooting In Michigan

Head coach Joe Philbin said the team is “excited” about Carroll’s potential, despite the second-year player seeing the field sparingly as a rookie and never supplanting Davis as a starting corner.

“We kind of have that saying (that) we’re looking for an honest days work out of the guys when you come into the building and he certainly fits the ball there in that regard,” Philbin said. “I thought his coverage during the preseason has been relatively tight on guys.”

Still, depending on Carroll to become a corner on the same level as Davis, despite Vontae’s poor conditioning in camp, may be a stretch. But Philbin has confidence in the secondary coming together under new defensive coordinator Kevin Coyle’s system.

READ MORE: Miami Art Week Kicks Off With VIP Party

“It’s a work in progress, no question about it,” Philbin said. “It’s new for them. I like the progression that Kevin had taught. I really like the way the guys teach.”

Besides the cornerback position, safety has been a perpetual problem for the Dolphins. In a division that features Rob Gronkowski, Aaron Hernandez, and Dustin Keller, poor safety play will kill any defense. But Philbin seems ready to go with the young secondary.

“Reshad Jones had a really good practice today,” Philbin said. He’s at that position, again, down the middle of the defense, his communication skills (are important). I think he’s had a strong training camp. It’s a group that’s obviously going to be challenged on Sunday and looking forward to seeing how they respond.”

Miami will be facing a Houston Texans offense that has consistently ranked in the Top 10 in the league in points over the past three seasons. Led by quarterback Matt Schaub, wide receiver Andre Johnson, and running back Arian Foster, the Texans have become the best team in the AFC South.

MORE NEWS: ‘Camping In A Glamorous Way’: Hollywood Condo Residents Keep Chins Up After Fire Leaves Them In The Dark

The Dolphins will respond with a rookie quarterback, running back Reggie Bush, and a largely unknown group of wide receivers against one of the top defenses in the NFL. Needless to say, the Dolphins are facing arguably the biggest challenge of any team in the NFL on Sunday.