EARTH CITY, Mo. — The worst fears for the Rams were realized Monday when coach Jeff Fisher confirmed that left tackle Jake Long and wide receiver Brian Quick will miss the remainder of the season with injuries they sustained Sunday in St. Louis’ 34-7 loss to the Kansas City Chiefs.

Long tore his right anterior cruciate ligament in the second half, the same injury he experienced in the 15th game last season against the Tampa Bay Buccaneers.

Quick, who made a quantum leap this season after struggling in his first two years after being the first pick of the second round in 2012, tore his rotator cuff and separated his left shoulder. He will undergo surgery.

“He was very productive,” Fisher said of Quick. “He took advantage of all the opportunities. He made tough plays, tough catches, and we’re going to miss him. As is the case when you have injured players, people step up, so we’ve got to have people step up.”

Receivers remaining on the roster are Kenny Britt, Tavon Austin, Chris Givens and Stedman Bailey. There is a possibility Austin Pettis, who was released last week, could be re-signed.

Replacing Long, rookie Greg Robinson will be the left tackle going forward, the position he played at Auburn. Robinson started the last two games at left guard, but he slid over to tackle when Long was injured.

“I thought he was fine (against Kansas City),” Fisher said. “He had some issues; they had outstanding rushers, but he was strong and stout. That’s what he does. He’ll have a week to work on the footwork and things like that this week. He went out there and knew what to do and came out of the stack on a screen and executed a block.

“You can see his athletic ability when he made the tackle on the interception. At the tackle position, he’ll be fine.”

Unfortunately for the Rams, Long and Quick weren’t the only players injured against the Chiefs. Four other starters left and didn’t return: right guard Rodger Saffold (shoulder), center Scott Wells (elbow), free safety Rodney McLeod (knee) and defensive end William Hayes (foot).

In addition, free safety Cody Davis left the game with a concussion after replacing McLeod, and he will go through the NFL’s concussion protocol. Hayes’ injury wasn’t announced during the game, but he left the locker room after game on crutches.

Fisher said more tests are being done on those players and added, “We’re going to have a number of players that will not be available for practice in the middle of the week, so we’ll just go kind of day-to-day with them.”

The Rams were already playing without starting cornerbacks Janoris Jenkins and Trumaine Johnson, so three of the four secondary starters weren’t available after McLeod left the game. Potential nickel back Brandon McGee was placed on reserve/injured Saturday after aggravating a foot injury last week in practice that cost him the previous four games. Jenkins sustained a knee injury the previous week against the Seattle Seahawks, while Johnson hasn’t played since injuring his knee in the same preseason game against the Cleveland Browns on Aug. 23 during which quarterback Sam Bradford torn an ACL.

The starters at cornerback were sixth-round pick E.J. Gaines, Johnson’s replacement since the start of the season, and undrafted free agent Marcus Roberson. Rookie second-round pick Lamarcus Joyner was the nickel back before switching to free safety after McLeod and Davis were injured.

Fisher said both Johnson and Jenkins might be available for Sunday’s game at San Francisco.

“(Johnson) made progress last week,” Fisher said. “Matter of fact, well before pregame, he had a really good workout with (secondary) coach (Chuck) Cecil, so there’s a chance he could come back. I think Janoris has a chance as well.”

As for Davis, Fisher said, “We had good results this morning, so he felt better.”

Hayes has been the replacement for Chris Long, who injured an ankle in the season opener and is on reserve/injured, designated for return. Long is not expected to be ready to play until the last four or six games of the season.

Meanwhile, Barrett Jones got the first game action of his career on offense for Wells.

When he was selected in the fourth round of the 2013 draft, Jones was recovering from foot surgery that was performed shortly after Alabama’s appearance in the national championship game. He played in three games on special teams late last season, worked to increase his strength in the offseason, but then experienced a setback and underwent back surgery in August.

Jones was active for the first time this season against Seattle, largely because backup center Tim Barnes injured a shoulder against San Francisco the previous Monday.

Said Fisher, “I thought Barrett did a nice job inside with his calls. (He) did a nice job directing traffic and working with protections.”

Finally, with Saffold out, Davin Joseph played right guard against the Chiefs, while Mike Person was at left guard after Robinson became the left tackle.