Earlier on Wednesday, a team source told ESPN.com's Matt Mosley that Phillips would take over play-calling duties from defensive coordinator Brian Stewart, but the coach wouldn't confirm or deny that later in the day.
"I'm going to try to do more," Phillips said. "I think I can help more than I have. When I step back and look at it I say, 'I'm losing some of my expertise.' Even though I'm in there on a lot of the meetings, I'm trying to be more proactive."
In the wake of Sunday's 34-14 loss to the St. Louis Rams, Phillips decided to do more, but he would not commit to what that meant.
"I don't want to get into who does what," he said.
Asked if he would take a more active role in the defense in general, Phillips said, "I'd say more active, yes. I'm going to concentrate more [on the defense] I guess you could say I think I can help more than I have. I'm trying to be more proactive."
On Monday, Phillips said changes could be on the horizon for the Cowboys, as the preseason Super Bowl favorites fell to 4-3. At some point between that loss and Wednesday, according to sources, team owner Jerry Jones instructed Phillips to take over the play-calling duties from Stewart, who worked with Phillips in San Diego when he was the San Diego Chargers' defensive coordinator.
Considering offensive coordinator Jason Garrett has full control of his side of the ball, there's little doubt Phillips already was spending most of his time with the defense. That's why he described this change as merely a move to "concentrate more, I guess you'd say."
"It was one of those things you think you're in there but maybe I wasn't enough," he said.
The Cowboys were ninth overall in defense in 2007, but this season they've lost several key players to injuries and one to a suspension. The team's best cornerback, Terence Newman, has been out with a sports hernia and Pro Bowl safety Roy Williams is out for the season with a broken forearm. Adam "Pacman" Jones replaced Newman, but then he was suspended indefinitely by the league for his role in a fight with a team-hired bodyguard.
Jones brought Phillips to Dallas, in part, because the Chargers had a league-record 61 sacks in 2006. Phillips promised to take underperforming players such as Williams and make them more effective. But in losing three of the past four games, the Cowboys have been gashed in the running game and victimized for big plays in the passing game.
The Cowboys are ranked fourth in the league with 20 sacks, but it hasn't translated into victories. They are 16th overall against the pass and have only two interceptions. The Cowboys rank 13th against the run. The Cowboys gave up 30 points only twice in all of 2007; they've already done so three times this season.
"We've got to fix what we have right now," Phillips said.
While Phillips may have resisted taking over play calling initially, he may not have had a choice. And it may have been awkward for Stewart, a relatively inexperienced defensive coordinator, to call plays when he was surrounded by so many ex-defensive coordinators, including Phillips, secondary coach Dave Campo and defensive line coach Todd Grantham.
For the foreseeable future, Stewart will remain defensive coordinator.
Searching for answers, Phillips said the staff reviewed every defensive play this season. What did they discover?
"There are things we need to do differently," he said. "Some of them are technical. Some of them are basic things. We'll try to work on some of those things and alleviate any of the mistakes we made."
Special teams have been a problem, too. Last week's change was to have position coaches take a more active role on special teams, too.
"We're going to carry that on, trying to look at things that will help us do better," Phillips said. "That is part of what you have to do."
Phillips once famously billed himself as "Mr. Fix-It." Now, at Jones' behest, he has an opportunity to get his hands dirty and turn the Cowboys' season around.
Matt Mosley writes about the NFC East for ESPN.com.