ALAMEDA, Calif. -- A "frustrated" Mark Davis said he stands behind general manager Reggie McKenzie and new interim head coach Tony Sparano as the Oakland Raiders try to bounce back from a 0-4 start and the firing of coach Dennis Allen.

However, Davis said it is imperative that the Raiders improve.

"The way we were losing was frustrating," the Raiders owner said after the news conference to announce Allen's firing and Sparano's hiring for the rest of the season. "I think it's just the way we lost some of the games, yeah, I think we weren't in them. To me, that's not what the Raiders are. ... In my analysis, I think we do have players that can play in this game. And I just think that there may be some changes in how the schemes are utilized. Dennis is the one who has taken the fall for it."

Davis said it was McKenzie's decision to fire Allen and that he agreed. McKenzie chose Allen in 2012 after Davis made McKenzie the primary decision-maker of the franchise in the first move after the death of his father, Al Davis, in November 2011.

Allen was 8-28 as the Raiders coach and they have lost a league-high 10 games dating to last season.

Asked if it was a mistake to keep Allen after consecutive 4-12 seasons, Allen said, "No, that was Reggie's decision, and you see where it ended up. So, I don't know if you'd call it a mistake."

McKenzie said in the news conference that he will hire the next coach. Yet he said he realizes nothing is guaranteed with his own job security.

"A lot rides on me," said McKenzie, whose drafting and free-agent signings have yet to pay dividends on the field in Oakland. "I brought Dennis here to win, and that did not materialize."

Sparano At A Loss Since Tony Sparano became the Dolphins' head coach in 2008, the teams he has been involved with have had just one season .500 or better. The past six seasons, his teams have finished below .500 every year: Team W-L Role 2008 Dolphins 11-5 HC 2009 Dolphins 7-9 HC 2010 Dolphins 7-9 HC 2011 Dolphins 4-9* HC 2012 Jets 6-10 Off. Coord. 2013 Raiders 4-12 Asst. HC 2014 Raiders 0-4 Asst. HC * Fired after Week 14 -- ESPN Stats & Information

Davis said he has not considered firing McKenzie. However, if the losing continues, Davis made no promises. He said it could be considered "a step backward or step forward" to fire McKenzie, depending on how this season goes. Davis said he will take an increased role in hiring decisions going forward.

Davis said he wasn't sure when asked whether he would contact former Oakland coach and current ESPN "Monday Night Football" analyst Jon Gruden.

"I don't know," Davis said. "He may reach out to me, I may reach out to him. I may reach out to anybody. That's the future, and I'm not going to talk about future coaches."

Davis said McKenzie can start looking for a permanent new coach now to hire after the season. But he also said Sparano will have the opportunity to show the team he can be the permanent coach. Sparano, 52, was the head coach in Miami from 2008 to 2011. He went 29-31 there.

Sparano, who has been the Raiders' assistant head coach/offensive line coach since last season, said he believes the Raiders need a "philosophy" change. He was not ready to announce what that was. However, Davis said he believes the Raiders need to work on schemes, and Sparano hinted that some could change.

"I think my evaluation is that we do have some players," Davis said. "And we may be running some schemes that are putting a square peg into a round hole, and that maybe with some changes in that type of environment we might be able to get something out of these players."

Asked what the Raiders' biggest problem is, Sparano said the team had forgotten "how to win. ... They have to get that taste back."