By trading cornerback Vontae Davis, the Dolphins turned a potential strength into a serious question, weakening their back line of defense in a league where ill-equipped teams can get carved up by potent passing games.

Shipping Davis to Indianapolis for a second-round pick and a conditional sixth-rounder leaves the Dolphins not only with erratic Nolan Carroll as their No. 3 cornerback behind starters Sean Smith and Richard Marshall, but also without an experienced No. 4 corner.

For now, Miami’s fourth corner is Quinten Lawrence, who has never appeared in an NFL game after being drafted in the sixth round by the Chiefs in 2009.

The perception is that Davis was traded partly because of questions about his professionalism. HBO’s Hard Knocks showed defensive backs Lou Anarumo telling Davis earlier this month that he needs to “change his attitude.” Coach Joe Philbin was bothered that Davis needed to leave a practice to go to the bathroom.

Still, Philbin insisted Monday that “Vontae and I never had any confrontations, never had any real issues.” But Philbin also said “part of the whole process is figuring out who’s a good fit.”

Philbin was asked if the Dolphins worried about trading a quality cornerback when there’s a premium on defensive backs in the league.

“We considered that fact,” Philbin said. “We had a comfort level with some of the guys we had on the roster. There’s always risk when you make a move of this nature.”

Philbin indicated he endorsed the trade: “I fully support the direction in which we moved.” He said Jeff Ireland “is very inclusive” in personnel moves and that “everything is a joint effort.”

Meanwhile, Philbin made it clear to his players two weeks ago that he did not want them criticizing personnel moves publicly. So none of them said anything negative on the record Monday, though one veteran player questioned the move privately.

Asked if he is discouraged the Dolphins traded a quality player for a draft pick who will not help them this year, Reggie Bush said, “It’s tough, obviously. It’s tough.” A Dolphins publicist, unaware of the topic being discussed, then called across the room, ordering the interview to end.

Karlos Dansby, who criticized Chad Johnson’s release two weeks ago, gave a more politically correct response Monday.

“I’ll leave that up to you all,” Dansby said when asked if the trade discouraged him. “I don’t know what the situation was or what occurred to cause the trade.

“He’s a great player, one of the best corners in the game. I’m not sure about the direction of the team. That’s not my place. My place is to play hard and be the leader of men.”

In a scene chronicled on Hard Knocks, Dansby, Bush and Jake Long met with Philbin after Johnson’s release, with Bush telling Philbin: “If there’s a guy in trouble, can we help them in some way before you make a decision? We might have been able to save them.”

Philbin seemed to agree and suggested the creation of a leadership council effective the first week of the regular season.

But Dansby said Philbin never discussed the trade with him before it happened.

“There’s nothing I can do to control that,” he said. “It’s not my place to recommend or OK a trade.”