While it was supposed to be the rookie debut for the left CB Morris Claiborne, it was right CB Brandon Carr who stole the defensive show in the first half.

He actually stole two Philip Rivers’ passes in the process.

Carr’s two interceptions helped the Cowboys to a 10-0 halftime lead over San Diego Saturday night at Qualcomm Stadium. It extended the Cowboys’ shutout streak to six quarters in the preseason.

Carr’s first pick occurred on an underthrown ball by Rivers where he made up ground to snag the ball and returned it 17 yards. He later had a hot-potato pick where he deflected it four times before hauling it in.

Rookie debut: The Cowboys unleashed their first-round pick Morris Claiborne, who started at left cornerback after missing Monday’s opener with a knee injury. Claiborne made a tackle on the second possession on a short screen, and then another on a slant. He did have great coverage down the field on Malcolm Floyd, forcing Philip Rivers to go to the right side, where Brandon Carr made a spectacular interception.

Turning heads: While Felix Jones continues to look rather unimpressive, it’s backup fullback/tailback Jamize Olawale who keeps flashing progress. Olawale scored the first and only touchdown of the preseason, rushing for 15 yards on five attempts. He also caught two balls for 19 yards.

The former wide receiver at North Texas, Olawale has been used in different spots, and could have an H-back type role. His chances of making the 53-man roster seem to increase by the week.

Sitting out: The Cowboys rested a few more injured players for Saturday’s game, most notably TE Jason Witten (lacerated spleen), who will miss all of the preseason. Other key players held out include OLB DeMarcus Ware, OLB Anthony Spencer, WR Miles Austin, DT Jay Ratliff and G Nate Livings. Ware recently sustained a hamstring injury, but owner Jerry Jones said he would play if this were a regular-season game. The same likely goes for Spencer, Austin and Ratliff.

Other injured players include RB Lance Dunbar (hamstring), RB Phillip Tanner (hand) and OT Jermey Parnell.

Fill-in captains: With Jason Witten and DeMarcus Ware held out of the game, the Cowboys used Gerald Sensabaugh and Doug Free as pre-game captains, to go along with Tony Romo, Sean Lee and Danny McCray.

For more Cowboys information follow Nick Eatman on Twitter @CBSSportsNFLDAL.