Two days after then-No. 6 Oregon fell to unranked Oklahoma State in the biggest upset of this college football season to date, Ducks coach Dan Lanning said Monday that there has been a "lack of leadership" across his team through two games.

"And that starts with me," Lanning said.

On Saturday, Lanning reacted to his team's lackluster performance by saying, "We got our ass kicked in a lot of areas." After watching the film, Lanning did not hold back on his assessment of Oregon's effort in the 39-31 loss.

"It really looks very similar to what it felt like on the field," Lanning said. "We did not perform at any level that was winning football. ... Sometimes you've got to learn hard lessons through hard performances, and this is -- you know, this is by far the worst performance that we've had since I've been here."

The Ducks, who struggled to beat Boise State in Week 1, were outgained by the Cowboys 554-281 and mustered only 90 yards on the ground. Penalties once again plagued them, as they committed seven for 66 yards. Once the Cowboys grabbed the lead in the fourth quarter, the ensuing three drives for Oregon's potent offense came up empty.

Oregon also was 0-for-3 on fourth-down conversions, including a controversial decision by Lanning to go for it on 4th-and-8 at the Ducks' own 33-yard line. On Monday, Lanning said he regretted going for it. The failed conversion all but sealed their fate.

"Wrong decision on my part," Lanning said. "So I learned, too."

Amid chatter that quarterback Dante Moore has been tipping run or pass plays with his pre-snap stance, Lanning said the Ducks have to do a better job policing and improving that, too. Asked why Moore had not spoken to the media after the loss, Lanning became animated.

"Did you know he was getting two IVs after the game?" Lanning said. "He was dehydrated."

The shocking loss dropped Oregon, which was widely considered a championship contender and ranked No. 2 going into the season, all the way down to No. 21 in the Associated Press poll.

"Stop looking into the future. Everybody wants to make a prediction before the season starts. You know, it doesn't matter until you play the games," Lanning said. "We have the capability to be good. We have good enough players. We have good enough coaches. I haven't coached them well enough. I haven't done a good enough job, so I know I can do better. So that's where it starts. But it doesn't matter unless we focus on today. Let's stop worrying about tomorrow. Let's stop worrying about the end of the season. Let's worry about today."

Beyond dealing with the aftermath of the loss on a short week (Oregon hosts Portland State on Friday night), the Ducks also have to overcome their first major injury setback of the season. Lanning announced Monday that starting offensive lineman Trent Ferguson is "probably" out for the season because of a knee injury.

"I'm anxious to go play. I think all of our players are anxious to go play," Lanning said. "I'm certainly anxious to get our guys back out in the field."