Blaine Gabbert overcame a shaky start to throw a 43-yard touchdown pass to Vance McDonald before the Houston Texans rallied in the second half against San Francisco’s reserves to beat the 49ers 24-13 on Sunday at Santa Clara, California, in the exhibition opener for both teams.

Brock Osweiler didn’t fare as well in his Texans debut, failing to lead Houston to any points in three drives. Houston got on the board early when John Simon returned a fumble by Carlos Hyde 41 yards for a touchdown but struggled to generate any offense with its starters.

With Colin Kaepernick sitting out with tightness in his throwing shoulder, Gabbert got the stage to himself in the battle to win San Francisco’s starting quarterback job for first-year coach Chip Kelly.

Gabbert, who started the final eight games last season, did little to improve his position in the first two drives. He was off-target on his first two passes as San Francisco went three-and-out in 41 seconds on the opening drive and started the game 1 for 6 overall.

But he was much more effective on the third drive when he scrambled 13 yards for a first down and then hit McDonald for the long score when Benardrick McKinney slipped in coverage.

Gabbert finished the game 4 for 10 for 63 yards and a touchdown.

Osweiler, who signed a $72 million, four-year contract with Houston in the offseason, went 4 for 7 for 27 yards. He took one sack and left for good after throwing an incomplete pass to Braxton Miller on fourth down early in the second quarter.

Tom Savage threw two TD passes in the second half for Houston, connecting on a 9-yarder to former California receiver Stephen Anderson and a 9-yarder to Akeem Hunt in the fourth quarter.

Rookie watch: Texans: Miller, a third-round pick, had four catches for 34 yards, including an acrobatic 24-yard gain in the third quarter from Savage. First-round pick Will Fuller had just one catch for 4 yards. 49ers: First-round DL DeForest Buckner was pushed around a bit in the running game and finished with one solo tackle and two assists.

Injury update: Texans: Several Houston starters sat out the game, including DL J.J. Watt (back), LB Jadeveon Clowney (knee) and rookie C Nick Martin (back). MLB Brian Cushing also did not dress for the game but was not hurt. 49ers: Backup QB Thad Lewis was 12 for 21 for 97 yards before leaving the game with a lower-leg injury. … DL Arik Armstead sat out the game after being limited last week in practice by a shoulder injury.

Position battles: Texans: DL Christian Covington made a good showing as he got a look with the starters with Watt sidelined. Covington forced the fumble by Hyde that led to Houston’s first score. 49ers: RT Anthony Davis, who sat out last year in temporary retirement, played with the second string behind Trent Brown in his first game in more than 19 months and was beaten by Eric Lee for a sack late in the first half.

QB Cousins: ‘I want the Redskins to be like the Spurs’

In the first training camp he entered as the Washington Redskins’ starting quarterback, Kirk Cousins has not only enjoyed the absence of drama that marked previous preseasons, he’s hoping it becomes the team’s standard.

“I’ve told my teammates that I’d like to be the San Antonio Spurs of the NFL, be super boring and maybe people at the end of the season just go: `Wow. They had a really good year and no one talked about it,“’ Cousins said.

The Spurs, one of the least flashy teams in the NBA, have won six championships since 1999.

Washington held its last workout in Richmond that was open to the public in sweltering heat that approached triple digits, and Cousins declared the team’s time in Virginia’s capital “a productive 2 1/2 to three weeks.”

They will have one more workout Monday before packing up and heading to their Ashburn, Virginia, headquarters.

“I think we got a lot of work done. We covered a lot of situations and got to see so many different players contribute and get a lot of experience and growth,” Cousins said between Sunday’s morning walk-through and afternoon practice. “It was a productive camp and hopefully we can finish strong here with the last couple of practices.”

The 27-year-old Cousins, declared the starter late in training camp last season, started all 16 regular-season games for the Redskins, throwing for 4,166 yards and 29 touchdowns with 11 interceptions. He also led the team to a 9-7 record and the NFC East championship before Washington was beaten by Green Bay in a wild card playoff game.

Cousins played just two series in the Redskins’ 23-17 loss to Atlanta in their preseason opener, and completed all five of his passes. The Redskins were otherwise sloppy, committing 14 penalties for 123 yards and struggling to get their running game untracked, but Cousins said he’s confident the team will be able to move the football.

“Having a great defense, having a great running game, being able to control the line of scrimmage … the fundamental principles of football that have always been there are very important,” he said. “Obviously there are ways around it. You can still throw the ball effectively, use quick game and other things, but you’re going to be more consistent as a football team if you can control the line of scrimmage and run the football effectively.”

For the past four years, the Redskins featured Alfred Morris in their running game. When they opted not to re-sign him after last season, that left second-year back Matt Jones as the likely starter and lead ball carrier.

This early in camp, the offense under third-year offensive coordinator Sean McVay is still a work in progress, but Cousins likes the direction the team is heading.

“I’m very pleased with Sean and what he’s doing with our offense,” he said. “It’s so key as an offense to find an identity, find out what you do well, have a bread and butter, something you can hang your hat on, and I think we are starting to get there. We’re starting to feel that with the players we have and Sean’s done a great job of just continuing to evolve the offense to our strengths and weaknesses.”

The real test, he knows, won’t come until their regular season-opener on Sept. 12 against Pittsburgh.

“We’re trying to be ready for Week One but also get in a rhythm and find some completions and convert some first downs and move the football and hopefully score points, just like we would in any other situation,” he said. “We’re going to try to do that until they take us out of the game.”

Panthers’ DeHaven steps down as coordinator to battle cancer

Carolina special teams coordinator Bruce DeHaven will move into an advisory role with the team while continuing his battle with prostate cancer.

The team announced Thomas McGaughey has been promoted to special teams coordinator and Chase Blackburn to special teams assistant.

DeHaven will return to Buffalo, New York to receive cancer treatments with the hopes of returning to the team as an adviser in mid-September.

The 67-year-old DeHaven was diagnosed with prostate cancer in 2015. The disease later spread to his back. He previously took a leave of absence in May of 2015, but returned for Carolina’s NFC championship season.

McGaughey was hired as Carolina’s special teams assistant in February. He has 10 years of NFL coaching experience.

Blackburn joined the staff this year as an intern.