Opposing quarterbacks have completed 25 of 35 passes (71.4 percent) for 268 yards when targeting Carter this season, per Pro Football Focus.
"Bruce had some problems covering their guys," coach Jason Garrett said Monday, via the team's official website. "Two of their touchdowns were scored with (Danny) Woodhead on him, and he didn't cover him that well, and there some other things going on in our other coverages that he didn't do a good enough job on."
An NFC personnel man opined to ESPNDallas.com that Claiborne is "a good cover guy with top-flight weight, height and speed to cover," but he isn't a ballhawk and has trouble following the ball at times.
"They went to him too much in this ballgame, and they were too effective," Garrett said. "He's just got to play better, and he will play better."
Claiborne isn't winning any points with executive vice president Stephen Jones, who declared Monday that it's time for the cornerback's "injury thing to leave the scene."
The Cowboys understandably had lofty preseason expectations for both Carter and Claiborne as potential breakout stars. At the quarter-season mark, the two high draft picks now are under pressure to start carrying their weight on a defense that has shut down opposing rushing attacks.