Prescott learning from his mistakes

OXNARD, Calif. — Dak Prescott threw two interceptions just a few plays apart in a training camp practice, including an ill-advised pass across the field to a receiver just a few yards from the line of scrimmage.

Those picks, and the decisions that go with them, are under more scrutiny after the Dallas Cowboys quarterback followed his remarkable rookie season with a somewhat pedestrian encore. And Prescott is among those doing the scrutinizing — each night at camp in the film room.

“When I go back, I'm being super-critical of myself, of the throws, of the placement, of where I should have went with the ball,” Prescott said Sunday. “I'm tough on myself. So when I go back tonight, all of that was OK, it's got to better and this is why it's got to better. And I take my notes, and I move forward.”

With the release of threetime Pro Bowl receiver Dez Bryant and the retirement of 15-year tight end Jason Witten , Prescott is working with a revamped group of receivers and unproven batch of tight ends.

Odds and ends

The Arizona Cardinals lost starting center A.Q. Shipley for the season with a torn right anterior cruciate ligament and will replace him with rookie Mason Cole. … The New England Patriots released wide receiver Malcolm Mitchell. The 2016 fourth-round draft pick played in 14 regular-season games as a rookie but spent all of last season on injured reserve. … The Atlanta Falcons agreed to a three-year contract extension with safety Ricardo Allen, who could have become an unrestricted free agent in 2019. … Tom Heckert, a former personnel executive for the Denver Broncos who also served stints as general manager for the Cleveland Browns and the Philadelphia Eagles, died Sunday night after a long illness. He was 51. Heckert stepped away from the Broncos at the end of last season after was after being diagnosed in recent years with amyloidosis, a rare disease that causes a buildup of amyloid proteins in the heart, kidney, liver and other organs.