GLENDALE, Ariz. -- Arizona Cardinals quarterback Kyler Murray was carted off the field with a noncontact knee injury less than 90 seconds into Monday night's game against the New England Patriots.

Murray is scheduled to undergo further testing on Tuesday, including an MRI, but a source told ESPN there is "little doubt that it's torn," referring to an ACL.

In his postgame news conference, Arizona coach Kliff Kingsbury said Murray's injury "doesn't look good, but we'll know more in the morning."

"Obviously, it didn't look good," Kingsbury said. "I've never seen him in that type of shape, so I assumed it wasn't good."

Murray went down after a 3-yard run to the right on the third play of the game. The clock read 13:39 while Murray was attended to by team athletic trainers and doctors. He wasn't touched before he went down.

"Anytime you see a noncontact injury, you know it's worse right away," Cardinals wide receiver DeAndre Hopkins said.

"That hurt. Kyler put a lot into this. He's been preparing his butt off to get back after the hamstring [injury that kept him out of Weeks 10 and 11], so for that to happen, I hate that for him. I know he'll recover and get back to himself."

Murray's teammates took a knee around him almost immediately, and Kingsbury was also on the field checking on the star quarterback.

The cart took Murray off the field toward the Cardinals' locker room as he sat on the back with a team athletic trainer. ESPN's Lisa Salters reported on the game broadcast that Murray was sobbing as he entered the tunnel on the cart.

"Just tough because he controls the offense," left tackle Josh Jones said. "He's a crazy guy out there. He can do so much. It was tough losing him so early. I hope he's OK. I don't know what was going on with him. I just hope he's OK."

Backup Colt McCoy entered the game in Murray's place. He threw for 246 yards on 27-of-40 passing with an interception against New England and was sacked six times in Arizona's 27-13 loss.

The 36-year-old McCoy had a 1-1 record as the team's quarterback when Murray was out for two games last month. McCoy is set to start the final four games for the Cardinals should Murray miss time. McCoy hasn't started at least six games in a season since 2011 and is set to do so at 36 -- a notion McCoy chuckled at.

He believes he's ready to take over the offense, especially with a week of practice ahead of him before Arizona travels to Denver to face the Broncos on Sunday.

"I've played for a long time and you always gotta be ready," McCoy said. "You never want to see the guy in front of you go down. You just don't. I've had a lot of opportunities in my career. I've gotten injured. So, I'm thankful to be on this team, on this squad and I love the guys that we have."

Kingsbury agreed that McCoy is ready.

"There's no doubt," Kingsbury said. "He's got a great feel for the system. I thought he did some good stuff tonight. It's always tough when you haven't had the reps during the week, but I thought he gave us a chance. Some of those plays that got called back, a couple of tough drops and then, obviously, the turnovers just put us behind the eight ball."

Murray is a two-time Pro Bowl selection who was the No. 1 overall pick in the 2019 draft out of Oklahoma. The 25-year-old signed a $230.5 million contract during the offseason that could keep him with the franchise until 2028.

Murray was playing in his 11th game this season. Coming into Monday's game, he had thrown for 2,359 yards, 14 touchdowns and seven interceptions.

The Cardinals have been plagued by injuries this season, particularly on the offense. They're missing four of their starting offensive linemen and lost tight end Zach Ertz for the season, also because of a knee injury.

"We've battled injuries all year long and the guys that are gonna go in there ... they're gonna fight 'til the very end," McCoy said. "I don't think there's any more than you can ask for and I'd be proud to go lead them."

The Associated Press contributed to this report.