Williams has only 14 catches for 249 yards and two touchdowns heading into the Cowboys' game at Philadelphia Sunday night.
Williams said Wednesday that Romo throws better passes to the team's other receivers, and he can't figure out why.
Romo said the two are working hard in practices, even doing extra work, but for whatever reason, the chemistry is not there.
"I don't look at the numbers," Romo said before Thursday's practice at Valley Ranch. "We've been through this before with people trying to intersect and divide a football team. This team is too strong from the core.
"I know the media is going to make certain things appear what they may not actually have been or things of that nature. This team is too committed to winning and too committed to improving to let anything like that or anything [the media] may present to us divide this team."
For the past two days, Williams has discussed his lack of a connection with Romo. He said Thursday that he was getting tired of talking about it.
"I didn't complain," Williams said. "I didn't complain that I didn't get the ball. I got seven opportunities in [last Sunday's win over Seattle]. All I said was that, when it comes to me, it's not there. The percentages ... back my case. I'm not saying it can't be fixed because that's what we do every day. We try to work on it and get it fixed.
"I'm not a T.O. [Terrell Owens] or I'm not trying to be a T.O. I don't know why people are trying to put me in that category because I'm happy to win. I've said that 100 times."
Calvin Watkins covers the Cowboys for ESPNDallas.com. E-mail firstname.lastname@example.org.