Dallas defensive tackle Jeremy Mincey keeps replaying in his head the sack that wasn't against San Francisco's Colin Kaepernick.
Mincey's near-miss symbolized the season opener for a unit that has been shaping up as a liability for the Cowboys a year after giving up the third-most yards in league history.
The Dallas defense was better than expected, but not good enough to overcome three first-half interceptions from Tony Romo and an early fumble by DeMarco Murray in a 28-17 loss.
Mincey, a free agent in his first year with the Cowboys, says the defense has something "to build off" for Sunday's visit to Tennessee.
The Cowboys have to replace linebacker Justin Durant, expected to miss at least two games with a groin injury.
AP NFL website: www.pro32.ap.org and http://twitter.com/AP_NFL