DAVIE, Fla. (AP) — Miami Dolphins coach Tony Sparano could only scratch his head. Offensive line coach Mike Maser put his hands on his knees, dropped his head and shook it in disgust.

At the end of Dolphins practice Sunday, only the defensive backs were smiling. Watching Miami's offense tends to have that effect.

The competition to become Miami's starting quarterback has shown little progress at the beginning of training camp. Newcomers Josh McCown and Chad Henne haven't excelled, John Beck had one of the worst practices in his professional career Sunday, and it appears the Dolphins are headed for another season with the quarterback situation murky.

"In a perfect world, you would like to have this thing settled before you get into maybe that second preseason game somewhere down the road," Sparano said. "But I don't think that's the way it's going to be."

The Dolphins have turned to 12 different quarterbacks since Dan Marino retired in 2000 — including Beck, Trent Green and Cleo Lemon last season — and instability at the position is perhaps why they have missed the playoffs a franchise record six straight years.

Sunday's practice didn't show any signs of improvement.

Beck threw more interceptions (3) than touchdowns (0), including back-to-back picks in limited action. Henne threw an interception and missed receivers, while McCown didn't take first-team snaps as part of Miami's rotating practice schedule. All the while Sparano hovered behind them, scrutinizing every move as he weighs his biggest decision as a first-year head coach.

"Each opportunity you get has to be very important. It has to be valuable to you," Beck said. "It's kind of like golf, each stroke is really important."

Miami has been shuffling quarterbacks through the first two days of training camp, with only two players taking first-team snaps during 11-on-11 drills. The limited days have made it all the more important for the quarterbacks to show they can deliver.

"It's like when you're (out) it's tough because obviously you have to stay involved mentally but you're out of it," McCown said. "It's almost like you're running a race and you feel like someone is gaining ground on you. You know you're going to get your turn tomorrow but it's just that weird feeling."

McCown is the favorite — but not by much — to start the season opener, having 31 starts in six NFL seasons. He started nine games last year for Oakland and signed a $6.25 million, two-year contract with Miami in February.

Beck, a second-round draft pick in 2007, started four games as a rookie. He went 0-4 as a starter last season, fumbling seven times and throwing three interceptions.

Henne, a four-year starter at Michigan, was taken in the second round of this year's draft. He agreed to a contract Saturday and reported in time for evening drills and to make a run at the wide-open starting job.

"It's very important to get it done and get into camp especially because I'm competing right now," Henne said. "It's best for me to get as many reps as I can and prove that I can play."

Sparano has tried to keep the pressure on the quarterbacks this training camp, knowing full well that lackluster play at the position has kept Miami from producing a consistent offense since Marino retired.

The coach hasn't been pleased with the play at quarterback, and he's hoping the pressure will create some separation.

"I think, and this is the way I learned it, that when you get too secure in your job, you probably don't do your job as well as you should," Sparano said. "I think the players I feel the same way about. So giving them challenges, doing some of those things that way, I think kind of keeps them on edge a little bit. And I think that's good for us right now."