DENVER -- Star running back Todd Gurley sat against the Denver Broncos on Saturday and his Los Angeles Rams lost their first preseason game, a 17-9 defeat to the reigning Super Bowl champions at Sports Authority Field at Mile High.

The Rams' first-team defense played well, but the entire offense was limited to only three field goals after going 7-for-7 in red-zone situations through the first two games.

Case Keenum was again efficient, and Jared Goff again had his ups and downs on a night that featured at least a handful of drops by the Rams' receivers. Leading 6-0, the Rams' second-string defense surrendered a quick touchdown drive against quarterback Trevor Siemian, who ended it with a 1-yard pass to Virgil Green with four minutes left before halftime. The Broncos then added a 50-yard field goal by Brandon McManus and a 7-yard touchdown run by Ronnie Hillman, who gave his team an eight-point lead with 6:57 left in the third quarter.

The Rams went for it on 4th and 12 at the Broncos' 12-yard line with just over four minutes left, but Sean Mannion's pass to Temarrick Hemingway went incomplete.

Jared Goff only completed 4-of-12 passes on Saturday against the Broncos. Justin Edmonds/Getty Images

QB depth chart: The Rams' depth chart has pretty much already been set, with Keenum the starter and Goff the backup. Keenum ran with the first team for the third straight game, going 8-of-12 for 77 yards in four series, two of which ended in field goals. Goff went 4-of-12 for 45 yards and is now 16-of-33 for 165 yards in three preseason games, adding a touchdown, an interception, a lost fumble and four sacks. Keenum is 18-of-24 for 188 yards, one touchdown, no interceptions and one sack in three games. Asked if he has seen anything so far that would make him alter his quarterback depth chart, Fisher said: "No."

Maybe that dude could start: Pharoh Cooper has already cemented himself as the Rams' No. 3 receiver and turned in a very impressive catch to assist Goff. Seven days after scoring his first touchdown -- by running an out and reaching for the pylon on an 11-yard score -- Cooper came across the middle, extended with his left hand, tipped the ball to himself and secured a catch on third down. The rookie out of South Carolina will certainly contribute this season.

Who got hurt? Goff took a hard hit by linebacker Vontarrius Dora just before letting go of the ball, falling directly on his back. A postgame X-ray revealed only a bruised tailbone, Goff told ESPN's Shelley Smith. Keenum was hit while jogging out of bounds by cornerback Aqib Talib, which was deemed a late hit, but was also fine. Cornerback Troy Hill, seemingly vying for one of the last spots on the Rams' roster, appeared to hurt himself while making a tackle nearing the midway point of the third quarter, but walked off on his own power. Fisher said none of his players suffered injuries that would keep them out an extended period.

A surprise player who impressed: Many have wondered when talented rookie tight end Tyler Higbee would eventually take over as the starter, but the man who currently has that job, Lance Kendricks, had a nice day with the first team, catching three passes for a team-leading 36 yards. Kendricks caught a 15-yard pass during the second drive and a 23-yard pass in the third drive.

When it was starters vs. starters, the Rams looked ...: Stout on defense. Michael Brockers, Robert Quinn and Aaron Donald recorded tackles for loss through the Broncos' first two drives, both of them three-and-outs. On the third drive, the Rams forced a turnover on downs, with Dominique Easley coming up with a big tackle. And on the fourth one, Trumaine Johnson provided exceptional coverage of Cody Latimer on a deep ball up the sidelines, tipping it to Cody Davis for an interception. Fisher said his team still had some issues in the running game, however. "We have to work on that."

One reason to be concerned: Goff doesn't seem to have progressed to the level of an NFL starter just yet, though you must take into account that three balls were dropped while he was in the game. Goff slid awkwardly on third down in his first drive, falling just short of a first down with T.J. Ward closing in. On Goff's second drive, he was bailed out by Cooper's sensational play and also on a key drop by Broncos safety Darian Stewart, who would've had an easy interception and likely touchdown on Goff's pass to the outside while deep in Broncos territory. On his third drive, Goff took a snap from the shotgun on third down and took a sack from his blind side.

No Gurley: Gurley's preseason will end with only one drive and four carries. The reigning Offensive Rookie of the Year was held out in Week 3 and also will not play in Week 4, which will take place from Minnesota on Thursday. That means Gurley will have gone 23 days without any game action by the time he takes the field for the Sept. 12 regular-season opener, on the road against the San Francisco 49ers on Monday Night Football.

A case of the drops: Duke Williams, Michael Thomas and Hemingway all had obvious drops, with Williams's -- while wide open on third down, on a perfect pass pass from Goff -- erased because of an unnecessary roughness called on the Broncos. "They're a concern," Fisher said of the drops. "If guys continue to drop the football, they can't play."

Inactives: Wide receivers Bradley Marquez and Nelson Spruce and offensive lineman Rob Havenstein didn't play, as expected. All three could practice this coming week.