The injury is not considered serious, and it is unlikely that the Colts will sign any quarterback off of the market. With Sorji on the sideline, Painter will be given the opportunity to replace Sorji as the Colts top back up quarterback.
As of now there is no guarantee that Painter will make the roster, and it is very unlikely that Chris Crane will make the Colts roster. Last season the Colts lost Peyton Manning to injuries during the preseason. I'm just glad it's not him again.