Derek Carr ruled out by Raiders

The Oakland Raiders are being cautious with rookie quarterback Derek Carr, choosing to sit him for Friday night's preseason game at Green Bay, coach Dennis Allen told the NFL Network on Thursday.

The second-round pick out of Fresno State suffered an injury to his ribs and a concussion last Friday against Detroit. Allen said Carr, currently the Raiders' No. 2 quarterback, passed the concussion protocol but is still sore from the rib injury.

Carr practiced Monday, Tuesday and Wednesday.

Allen said Carr made improvements from Week 1 to Week 2 in the preseason. If his injury doesn't worsen, Allen expects him to play extensively in the preseason finale against Seattle on Aug. 28.

Matt McGloin will take over for starter Matt Schaub, likely in the third quarter, against the Packers.