Chargers cornerback Michael Davis takes a step back in second preseason game

Second-year cornerback Michael Davis, who played only 36 snaps as a rookie last season, has earned rave reviews for his improved play in training camp this summer.

“Like night and day,” Chargers coach Anthony Lynn said last week of the 6-foot-2, 195-pound Davis, who signed as an undrafted free agent out of Brigham Young in 2017. “He’s a guy who is playing with more confidence. He’s more physical. He’s becoming very dependable.”

With starting cornerback Trevor Williams sidelined by an ankle injury, Davis had an opportunity in the first two preseason games to play with the first-team defense. Davis had two tackles — one for a loss — and one pass breakup in the exhibition opener at Arizona last week.

But he appeared to take a step back in Saturday night’s 24-14 victory over the Seattle Seahawks in StubHub Center.

Davis was flagged for a pass-interference penalty midway through the first quarter when he got too physical with Brandon Marshall down the left sideline.

Early in the second quarter, both Davis and free safety Jahleel Addae were draped over David Moore, who somehow managed to haul in a 52-yard pass from Seahawks quarterback Russell Wilson.

Moore then beat Davis down the left sideline for a 19-yard pass play that gave Seattle a first-and-goal at the one-yard line, but Seattle fumbled the ball away on the next play.

There were two bright spots for Davis — he did break up a pass with about two minutes left in the first half, and it wasn’t as rough a night as Davis had in last season’s 31-point exhibition loss to Seattle, when Davis got beat deep five times for 144 yards.

Head-hunter

Jaylen Watkins, the former Philadelphia Eagles defensive back who signed with the Chargers as a free agent, got the start at free safety and made an immediate impact Saturday night, but not in a positive way.

On the first play of the game, Wilson connected with Jaron Brown on a crossing route for a 29-yard gain. Watkins made a crushing tackle of Brown but led with his helmet. He was flagged 15 yards for lowering his head, a violation of the NFL’s new helmet rule.

The penalty gave the Seahawks a first down on the Chargers’ 31-yard line on a drive that ended with Jason Myers’ 33-yard field goal.

Watkins made two first-half tackles, but his night ended with 2 minutes 41 seconds left in the second quarter when teammate Melvin Ingram fell on Watkins’ right leg on a play in which Wilson was sacked for a four-yard loss.

Watkins had to be helped off the field, and he was taken to the locker room on a cart. He was diagnosed with a right-knee injury.

Second chances

Running backs Austin Ekeler, Justin Jackson and Russell Hansbrough were held out of Saturday night’s game, giving undrafted rookie Detrez Newsome a chance to make a second impression after playing 35 snaps and scoring a touchdown — which he punctuated with a backflip — in the exhibition opener.

Newsome, who rushed for 3,728 yards and 37 touchdowns in four seasons at Western Carolina, had only two carries in the first half, but one was an eight-yard draw to set up Melvin Gordon’s two-yard touchdown run that gave the Chargers a 7-3 lead with 5:52 left in the first quarter.

Newsome carried 17 times for 69 yards and caught three passes for 22 yards in the second half, including a 31-yard run that set up Roberto Aguayo’s 39-yard field goal with 30 seconds left.

Etc.

Old habits die hard. The Chargers called time out with 55 seconds left in the first quarter Saturday night. Referee Tony Corrente announced, “Time out, San Diego,” which drew a hearty round of boos in StubHub Center. … Linebacker Jatavis Brown had three tackles, one sack, two quarterback hits and one tackle for loss in the first half. … Rookie linebacker Kyzir White, a fourth-round pick out of West Virginia who was slowed last week by sore knees, did not dress for the game. White played a team-high 39 snaps in the exhibition opener, making four tackles. Starting defensive end Joey Bosa (foot injury) and cornerback Trevor Williams (ankle sprain) remained sidelined. Receiver Dylan Cantrell, safety A.J. Hendy, tight end Cole Hunt and fullback Anthony Manzo-Lewis also didn’t dress. … The Chargers held a moment of silence before the game for Faye Spanos, the mother of owner Dean Spanos who died this month.

mike.digiovanna@latimes.com

jeff.miller@latimes.com