IRVING, Texas (AP) 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.
Kaepernick threw a touchdown pass after stepping out of Mincey's attempt at an ankle tackle on the 49ers' first possession. They drove on Dallas again late in the second quarter for a 28-3 halftime lead, but the Cowboys didn't give up any more points and gave up 319 total yards.
That's saying something for a team that allowed 415 yards per game last year, among several ignominious stats.
''It's definitely a great game to build off,'' said Mincey, who signed with the Cowboys as a free agent this year after spending most of his career in Jacksonville. ''I think we've got a chance to do something.''
But that's the big question heading into Sunday's game at Tennessee, whether the Cowboys can keep it up.
The biggest names are gone - franchise sacks leader DeMarcus Ware to Denver after his release and linebacker Sean Lee to a season-ending knee injury in the offseason.
Dallas looked to free agency for help first, but without the money to get a headliner. Mincey came in along with a pair of interior linemen in Jeremy McClain and Henry Melton, who made the Pro Bowl in Chicago before a knee injury sidelined him early last season.
The Cowboys drafted defensive end DeMarcus Lawrence early in the second round in May, but he's out until midseason with a broken foot.
Despite Mincey's best efforts, Dallas sacked Kaepernick just once and didn't get any takeaways to offset Romo's rough day. Even when Romo is on, the defense could be in trouble without game-changing plays.
''Personally I don't think no team could survive without takeaways,'' Mincey said. ''We're going to work hard this week on getting takeaways and forcing takeaways.''
The front four should get a boost from Melton being on the field longer after he missed the entire preseason with a groin injury. McClain is likely to make his debut against the Titans after being out since early in training camp with a sprained ankle.
It looks like Dallas will have to wait at least another week on veteran end Anthony Spencer, who still hasn't returned to practice in his recovery from knee surgery almost a year ago.
The Cowboys have to replace linebacker Justin Durant, who is expected to miss at least two games after injuring a groin against the 49ers. The first option appears to be rookie fourth-round pick Anthony Hitchens, who played just five snaps in his debut after getting some first-team work throughout the offseason.
''We have a lot of different linebackers who we think are going to contribute for us,'' coach Jason Garrett said. ''They did the other day in the game, so we have some options. Guys have played different spots.''
While the run defense was respectable against San Francisco, high-priced cornerback Brandon Carr was beaten badly on a couple of big plays. Kaepernick was 11 of 13 in the first half.
''I thought a couple times we could've contested better in third-down situations,'' Garrett said. ''Other times we needed some more help underneath those guys on some of those third-down situations. But I think they did some good things.''
Enough that Mincey thinks better days are ahead.
NOTES: Special teams ace C.J. Spillman, who injured his groin against his former team in the opener, missed practice Wednesday. DE George Selvie (shoulder) was limited. ... FB Nikita Whitlock was released from the practice squad and replaced by WR Reggie Dunn.
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