LOS ANGELES -- A year can change so much. It was 364 days ago that the Los Angeles Rams hosted the Dallas Cowboys for their preseason opener at Los Angeles Memorial Coliseum. Jeff Fisher patrolled the sidelines, Case Keenum started at quarterback, Dak Prescott was merely a rookie fill-in, and 89,140 people were in the stands, representing the largest crowd ever to watch an NFL exhibition game on American soil.

The Rams hosted the Cowboys to begin the preseason once again on Saturday, but it was Sean McVay as head coach, Jared Goff as the starting quarterback, Prescott among the resting star players, and 62,888 at the game -- a reflection of the 4-12 season that sapped some of the excitement for the local team in this city. The new-look Rams ultimately came away with a 13-10 victory, thanks to an impressive defensive performance and a late Sean Mannion drive that set up a 36-yard field goal by backup kicker Travis Coons.

Third-round pick Cooper Kupp, left, looks to have locked down a role as a slot receiver for the Rams and had two catches for 35 yards Saturday against Dallas. AP Photo/Mark J. Terrill

Below are some key takeaways.

QB depth chart: Goff got two series in very quickly. He went three-and-out, then the Cowboys muffed a punt, allowing him to take over on the Cowboys' 33-yard line. Goff then completed a 19-yard pass to Cooper Kupp on play-action, putting the Rams in the red zone. He later threw a pass to Robert Woods off a quick slant, which Woods fumbled before it was recovered by Kupp in the end zone. That was it. Goff went 3-of-4 for 34 yards. His backup, Mannion, saw extended action and played very well against Cowboys backups, going 18-of-25 for 144 yards.

When it was starters vs. starters, the Rams looked ...: not too different from last season, but it was a small sample size. Their defense -- without Robert Quinn, Mark Barron and Aaron Donald (a camp holdout) -- played well and aggressively against a Dallas offense that didn't have Prescott, Ezekiel Elliott, Dez Bryant and Jason Witten. On offense, Todd Gurley gained only 2 yards on four carries. And Goff kept most of his throws pretty short.

One reason to be concerned: The Rams' offensive line might not have much room for injury. Their second unit struggled, particularly backup center Austin Blythe, who made a high snap to Mannion that prompted the Rams to lose 28 yards. And reserve tackle Pace Murphy had a really tough day, allowing at least three defensive ends to blow by him for vicious hits on Mannion. One of the Rams' key backups, Andrew Donnal, has been nursing a knee injury throughout training camp. If something happens to the 35-year-old Andrew Whitworth at left tackle, they could be in serious trouble.

That guy could start: Matt Longacre won't start, but he looks like he could be an important backup for Quinn and Connor Barwin at outside linebacker. Longacre, a seldom-used defensive end the last two years, got extended playing time with Quinn and rookie Samson Ebukam out and did a nice job of getting around the edge to create disruption. Quinn and Barwin have combined for 14 NFL seasons and will be asked to do a lot in new coordinator Wade Phillips' system. The Rams need guys to step up behind them so they can stay fresh.

Rookie watch: Kupp and tight end Gerald Everett played well. Kupp, a polished third-round pick who already looks to have solidified a role as a slot receiver, caught a couple of passes for 35 yards. Everett, drafted 44th overall, had two catches for 12 yards and showed some nice moves in space. But the most impressive rookie was actually an undrafted running back, Justin Davis, who played on this same field while at USC. Davis hit holes quickly and decisively, gaining 70 yards on nine carries. But he fumbled twice.

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Fumbling around: The Rams fumbled the ball five times officially, and two more could've easily been added to that total. Davis fumbled twice, Woods fumbled near the end zone, Blythe fumbled on an errant snap, and Malcolm Brown fumbled on a run across the middle. Brown, currently Gurley's backup, also fumbled, then quickly recovered, after catching a short pass. Second-year tight end Temarrick Hemingway was called for a fumble after reeling in a long pass from Mannion, but it was overturned and ruled an incomplete pass. "We have to do a way better job of taking care of the ball," McVay said. "We only lost one tonight, but we put it on the ground way too many times."

Changes on the right side: Rob Havenstein was at right guard and Jamon Brown was at right tackle during the offseason program and in the early part of training camp, but McVay switched them on Sunday and kept them there throughout the week, including Saturday's preseason opener. Havenstein has played tackle throughout college and in the NFL, and Brown was a guard under Fisher these last two years. It looks like that's where they will stay. "I feel like Rob's really settling in nice at that tackle position, and Jamon will be our right guard right now unless something changes."

Welcome to L.A.: Wide receiver Sammy Watkins, acquired from the Bills in exchange for cornerback E.J. Gaines and a second-round pick Friday, made it to the Coliseum about three hours before kickoff and watched his new team play from the sideline. Watkins was introduced to a rousing applause on the video board in the fourth quarter. While addressing the media earlier, Watkins called the trade "a total shock, but I’m definitely excited, honored to be here. I really can’t wait to get started, just learning the plays and getting with the guys."