Saints QB Wallace struggles in debut after missing opener

Veteran quarterback Seneca Wallace’s long-awaited debut with the Saints didn’t go as planned Friday night at the Mercedes-Benz Superdome.

Wallace appeared to lose ground in his battle with Luke McCown for the backup job, twice turning the ball over in the third quarter, resulting in 10 points for the Oakland Raiders.

The Saints raced out to a 23-0 lead late in the second quarter, then held on to post a 28-20 victory.

“It was a tale of two halves for us offensively,’’ Saints coach Sean Payton said.

Wallace inherited a 23-7 lead from Drew Brees on the final play of the first half, only to see the Raiders close the gap to 23-20 by the time rookie quarterback Ryan Griffin of Tulane moved under center early in the fourth quarter.

Wallace’s turnovers came on back-to-back possessions in the third quarter. He fumbled at the Saints’ 1 after being blindsided by Raiders defensive end David Bass, who slipped behind rookie left tackle Terron Armstead for the sack and strip.

Raiders’ defensive end Ryan Robinson scooped and scored, cutting the Saints’ lead to 23-14.

On the Saints’ next possession, Raiders middle linebacker Omar Gaither snatched a deflected pass from Wallace out of the air for an interception at the New Orleans 21. A 46-yard field goal from Eddy Carmona trimmed the Saints’ lead to 23-17.

A strained groin kept Wallace out of the Saints’ first exhibition game against Kansas City. McCown (coach’s decision) did not play Friday night.

DID YOU NOTICE?: Line judge Sarah Thomas was part of Friday night’s officiating crew headed by referee Jerome Boger.

Thomas worked several practices at Saints camp earlier this month and is on the fast tracks to possibly joining the NFL next season. Thomas correctly called intentional grounding on Raiders quarterback Terrelle Pryor late in the third quarter.

SIDELINED SAINTS: Eight players did not dress Friday night — WR Marques Colston (foot), WR Courtney Roby (toe), ILB Curtis Lofton (unspecified), ILB Jonathan Vilma (knee), G Andrew Tiller (unspecified), C Eric Olsen (foot), OLB Junior Galette (knee) and OLB Martez Wilson (elbow).

PLENTY OF TIME: Unofficially, Brees had eight seconds of protection before unloading a 16-yard touchdown pass to rookie wide receiver Kenny Stills with 14 seconds left in the first quarter.

Brees initially stood in the pocket, then rolled left as the Saints’ line walled off a slow-developing the-man rush from the Raiders.

BY THE NUMBERS: 11 — Saints sacks after two exhibitions under defensive coordinator Rob Ryan, including seven Friday night.

By comparison, the Saints had four sacks after their first two exhibitions a year ago against Arizona (3) and New England (1) under defensive coordinator Steve Spagnuolo.

LAGNIAPPE: On the Raiders’ opening possession, which ended on downs, quarterback Matt Flynn of LSU twice missed wide open receivers that would have resulted in touchdowns. … Former Saints cornerback Tracy Porter, a native of Port Allen and one of the stars of Super Bowl XLIV, now is playing for the Raiders. He sustained a groin injury with 11:51 remaining in the second quarter and exited the game with four tackles. … Former Saints safety Usama Young also is on the Raiders’ roster … Friday night’s exhibition marked the Raiders’ first preseason trip to New Orleans.

ON TAP: Training camp officially ended with Thursday’s practice. The Saints are expected to return to practice at 4 p.m. Monday in preparation for their third exhibition on Aug. 25 against the Houston Texans at Reliant Stadium, Saints spokesman Greg Bensel said.