GLENDALE, Ariz. — Carolina Panthers starting left guard Amini Silatolu went down with a leg injury in the third quarter of Sunday’s 22-6 loss to the Arizona Cardinals.

The initial diagnosis is a sprained medial collateral ligament for the second-year player.

“Hopefully it’s not serious but we’ll find out,” Ron Rivera said. “We’ll get an MRI (Monday) morning and hopefully it’s nothing serious and we’ll just hold our breath.”

Silatolu was hurt with 5:48 remaining in the third quarter on a short pass to Steve Smith that was eventually called back for offensive pass interference. On the ensuing play, after Travelle Wharton came in as a substitute, Cam Newton was sacked in the end zone for a safety.

“It wasn’t Travelle who gave it up, so again, it’s one of those things where you have to look at the tape and see what happened, what exactly happened,” Rivera said. “Pressure came up from right up the middle.”

The Panthers have already had to play without Silatolu this season. He missed the season opener with a hamstring strain, and Carolina was forced to play guard by committee.

Playing sick : Defensive end Greg Hardy said he was “a little drugged-up” during the game but refused to use it as an excuse for his play.

Hardy fought a fever and an undisclosed illness all week and missed practice on Wednesday and Thursday. He had three tackles and one quarterback pressure but did not produce a sack Sunday.

He went up against Bradley Sowell, who was making his first career start, after the Cardinals traded left tackle Levi Brown to Pittsburgh. Sowell and Hardy had history together: the two played together at Ole Miss.

“He held his own,” Hardy said. “I did my thing as normal, and I didn't do it as good as I should have, hands down.”

Healthy scratches : Josh Norman was inactive Sunday for the first time in his career. With James Dockery back from injury (shoulder/thumb) and undrafted rookie Melvin White coming off a good game against the Giants, Norman was the odd cornerback out for the Panthers.

Also inactive was Frank Alexander. The Panthers have wanted to take a look at undrafted rookie defensive end Wes Horton, and Alexander has been inactive the past two games.

With those two inactives, Carolina had three of its seven draft picks from 2012 playing on Sunday. D.J. Campbell and Joe Adams are no longer on the team, leaving Silatolu, Brad Nortman and Luke Kuechly as the lone representatives.

Linebacking brothers : The Panthers essentially played their Week 3 contest against the Giants without linebacker Jon Beason, who got just one snap against New York.

Sunday, the Panthers literally played without him. Beason, a three-time Pro Bowler, was traded to New York in exchange for an undisclosed 2014 draft pick on Friday.

“It’s definitely a different situation not having Jon here, but I have five other brothers that are still here,” linebacker Thomas Davis said. “We go out and we play together and we play as a team. That’s what it’s all about: Playing with the guys that are inside this huddle.”

Observations

•  Mike Tolbert rumbled for a 20-yard gain late in the first half to help Carolina get in field-goal range. It was his longest rush in his two-year Panther career.

•  The “in the grasp” sack rule led to two sacks Sunday. Newton was sacked by Tyrann Mathieu despite getting away, and Palmer was sacked by Charles Johnson before fumbling.

•  Newton has been very good on drives to close out the first half this season. He led a 90-yard touchdown drive at Buffalo, a 65-yard touchdown drive against the Giants and went 47 yards in five plays to get a field goal to go into halftime with a 6-3 lead.

•  Ben Hartsock was called for holding on a 41-yard field goal by Graham Gano. At the end of the half, he and special teams coordinator Richard Rogers talked to the referees about the call.

•  Brandon LaFell had ice on his back in the locker room. He said he suffered a muscle strain in the first half after a hard tackle but is expected to practice Wednesday.

By the numbers

7 sacks by the Cardinals on Newton, tying his career high.

2 tackles each by Newton and Jordan Gross, both following turnovers.

95 Panthers rushing yards, the most allowed by Arizona all season.

6 losses by the Panthers in seven games when Newton throws for more than 300 yards.

Quotes

“There are a lot of things that I feel I could have done better. Getting the ball out is one of them.” – Carolina quarterback Cam Newton.

“They did a great job covering those guys up. (Newton) had to hold the ball longer than you’d expect.” – Arizona LB Karlos Dansby.

“We are fortunate to get 22 points. Our defense, with the safety and with the field position really helped us out.” – Arizona quarterback Carson Palmer.

“Sometimes when you don’t score touchdowns it takes the wind out of your sails and you have to settle for the field goal.” – Carolina coach Ron Rivera.

Jones: 704-358-5323; Twitter: @jjones9