Indianapolis Colts quarterback Andrew Luck is expected to miss the next two-to-six weeks with abdominal injuries suffered Sunday against the Denver Broncos, the team announced.

Surgery will not be required to treat a kidney laceration and a partial tear of an abdominal muscle.

The injuries occurred at the end of a fourth-quarter scramble. Luck's condition worsened Monday and the Colts sent him for testing.

Head coach Chuck Pagano suggested the timetable for Luck's return is fluid.

"We're going to keep listening to the doctors and evaluating his progress on a week-by-week basis," Pagano said.

Matt Hasselbeck will start in Luck's absence. The 40-year-old veteran started two games in October with Luck sidelined with a shoulder injury, winning both.

"We've got all the confidence in the world in Matt Hasselbeck and we're not going to put Andrew back out there until he's healed and ready to go," Pagano said.

The Colts are 4-5 and sit in first place in the AFC South.

The Colts signed quarterback Alex Tanney to their practice squad and could add him to the active roster at the end of the week to serve as Hasselbeck's backup.