New England Patriots owner Robert Kraft declared Monday that "I know that there is no smoking gun" that could prove the Super Bowl champions used underinflated footballs during the first half of the AFC championship game in January against the Indianapolis Colts.

Speaking to the media at the NFL owners meeting Monday, Kraft otherwise deflected questions about the NFL's ongoing football probe, directing all questions to the league office, but said he preferred to let the investigation run its course.

"I like to worry about things I can control," Kraft told reporters, as quoted in USA Today.

Kraft referred to his comments from the Super Bowl before adding, "We're worried about the 2015 season, and that's our focus."

At the Super Bowl, Kraft had requested an apology from the NFL if the league didn't definitively discover wrongdoing. To some, Kraft's remarks were surprising because of how close he is with NFL commissioner Roger Goodell.

Kraft was asked where things stand with his relationship with Goodell.

"I want to clarify. First of all, I think when I spoke a week before the Super Bowl, I was speaking to the league office. He's in charge. I think he has a pretty tough job. As a matter of fact, some of my friends say, 'There are two jobs I don't want, president of the United States or commissioner of the NFL.' He has a very hard job and I think he does a very fine job at what he does," he said. "It's tough, but he needs to make sure all the people working in the system are also doing it."

The NFL says it is still investigating how the Patriots used underinflated balls in the Indianapolis game but has no conclusions yet and no timetable for resolving the cheating accusations with the AFC title game now two months removed.

The league issued a statement that the Patriots have pledged full cooperation and have given the league information it requested and made personnel available upon request.

Kraft said in January that investigators were in Foxborough for three days in the buildup to the Super Bowl after he received a letter from the league informing him of the football probe.

"We provided access to every full- and part-time employee the league's representatives requested to speak with and produced every communication device that they requested to search," he said then. "I very much support the league's desire to conduct a complete investigation."

Information from The Associated Press contributed to this report.