Collins has completed 381 of 674 passing attempts (56.6 percent) for 4,479 yards, 22 touchdowns and 19 interceptions to compile a 76.0 passer rating in 47 games (20 starts). He is a former second round pick (45th overall) of the Buffalo Bills.
The veteran reportedly turned down the Bears last week when it became clear they wouldn't offer him guaranteed money. They signed Matt Gutierrez instead.
But a Saturday night preseason performance which included five sacks in the first half likely encouraged the Bears to change their mind on incentives.
Team officials said they'll announce the roster move later today.