Kreutz, who has spent 13 seasons with the Bears, appears to be on his way out of Chicago with contract negotiations going nowhere.
Said Kreutz's agent, Mark Bartelstein: "Right now, it doesn't look good."
"I think it's over," the source told the Tribune. "They seem dead."
Joining them soon will be Barber, who agreed to a two-year, $2.5 million contract with the Bears, a league source told NFL Network insider Jason La Canfora. Barber is the third former Dallas Cowboy to become a Bear this week, along with wide receivers Roy Williams and Sam Hurd.
Barber was released this week after spending six seasons with the Cowboys and running for 4,358 yards and 47 touchdowns -- sixth in the NFL during that span. He added 1,280 receiving yards.
"I kind of got my mind put to ease by (general manager Jerry Angelo)," Forte said. "He had been in talks with my agent since the end of the lockout and even before that, and he kind of said that a deal would get done. He assured us repeatedly that a deal would get done. Where I'm from and how I was raised, when somebody gives you their word, that goes a long way."
The youngest first-round draft pick in NFL history when he was taken 10th overall in 2007 at age 19, Okoye had a career-high 44 tackles in 2010, including three sacks. But the Texans spent six of their eight draft picks on defensive players, and new coordinator Wade Phillips plans to use Shaun Cody and Earl Mitchell at nose tackle, leaving Okoye out of the mix.
In four seasons with Houston, Okoye had 138 tackles, 11 sacks, two forced fumbles and two fumble recoveries.
Graham led Chicago with 25 special teams tackles last season.
The Associated Press contributed to this report.