IRVINE, Calif. -- Pharoh Cooper, solidified as the No. 3 receiver, and E.J. Gaines, basically locked in as the No. 2 cornerback, suffered injuries in the Los Angeles Rams' 17-9 loss to the Denver Broncos on Saturday that could keep them out for the start of the regular season.
Cooper injured a shoulder on an acrobatic catch and will be out "for a few weeks," Rams coach Jeff Fisher said during Sunday's availability. Gaines, who missed all of last season with a foot injury, suffered a quad strain, and Fisher said he "may miss some time."
Fisher said Cooper will "probably" miss the Sept. 12 regular-season opener, but wouldn't specify with Gaines, who was previously set back with a hamstring injury.
Starting left tackle Greg Robinson and cornerback Troy Hill, an outside candidate to crack the final 53-man roster, went through the league's concussion protocol in Denver late Saturday night. Both are expected to miss the final preseason game in Minnesota on Thursday, but Fisher said they're both "way ahead of schedule" and are "not having any residual effects."
Fisher would not comment on rookie quarterback Jared Goff having a postgame X-ray that revealed a bruised tailbone, the result of a vicious hit by Broncos linebacker Vontarrius Dora. But Fisher said Goff participated in a walk-through on Sunday, as did receiver Bradley Marquez, who injured his right ankle on a screen pass during the Aug. 20 game against the Kansas City Chiefs.
Cooper injured his shoulder while making a play on Goff's pass in Saturday's second quarter, a play that saw Cooper run across the middle, extend his left arm, tip the ball in the air and secure a 19-yard catch on third down. A multidimensional receiver who can also help out of the backfield and in punt coverage, Cooper is expected to play a major role in the Rams' offense this season.
"I don't know how long [Cooper will be out], but it looks like he'll probably miss the opener," Fisher said. "And we'll just see how quickly he can come back from that."
Gaines played in his first preseason game on Aug. 20 and ran with the first-team defense Saturday.
The 24-year-old had a standout rookie season in 2014 and is expected to start opposite primary corner Trumaine Johnson in 2016. But Gaines has struggled to stay on the field during training camp, first with an ailment to his hamstring and now another one to his quad. It could all stem from a long recovery from foot surgery.
"I'm hoping this is the last thing that comes up," Fisher said of Gaines. "He was extremely pivotal in his rookie year as a starter for us."
The recent ailments may force Fisher to carry an extra receiver or cornerback for the Sept. 12 opener against the San Francisco 49ers, a game that will be part of ESPN's Monday Night Football coverage. Teams must trim their rosters to 75 players by 4 p.m. PT on Tuesday and 53 players by 4 p.m. PT on Saturday.
Offensive lineman Rob Havenstein, who had been dealing with a foot injury, was recently taken off the physically unable to perform list and is expected to practice with the team over the next couple of days. Rookie receiver Nelson Spruce, who sprained his knee during an impressive performance against the Dallas Cowboys on Aug. 13, has been running and "may be close" to practicing with the team.
Despite his absence, Spruce still seemingly has a solid chance to crack the final roster.
"There's a lot to still consider," Fisher said. "We coveted Nelson out of the draft and we saw some things that we really liked, and then we saw them in the game. Unfortunately, he's missed time, so we're just going to have to address that this week."