Sources: Broncos QB Drew Lock has sprained AC joint in throwing shoulder

Denver Broncos quarterback Drew Lock joined a fast-growing list of injured players for the team when he was knocked out of the lineup Sunday with a right shoulder injury in the Broncos' 26-21 loss to the Pittsburgh Steelers in Heinz Field. Denver fell to 0-2.

And guard Dalton Risner might have spoken for all of his teammates, most of the team's faithful and just about anyone who saw what transpired Sunday, when he offered: "We've got guys going out, dropping like flies.''

Lock left Heinz Field with a sling on his right shoulder as sources told ESPN that Lock had suffered a sprained AC joint and could miss between two and six weeks, depending on what additional tests reveal. Lock is scheduled to undergo a magnetic resonance imaging (MRI) exam Monday morning.

The second-year quarterback was injured with just under eight minutes remaining in the first quarter. Lock was sacked by Steelers linebacker Bud Dupree and fumbled as he landed awkwardly on his right shoulder and arm.

Lock's right shoulder sagged slightly as he then walked to the sideline and was taken into the medical tent behind the Broncos' benches. He stayed in the tent throughout the next Steelers possession but was then taken to the locker room and did not return as Jeff Driskel took over behind center.

"It felt funny,'' Lock said. "... Came back in [the locker room], just tried to assess the situation, just see what we could do.''

Broncos coach Vic Fangio confirmed Lock will be taken for "some tests'' Monday, but Fangio said following the game that he did not have an update on the severity of the injury.

Lock's injury comes as linebacker Von Miller (ankle) and cornerback A.J. Bouye (shoulder) are already on injured reserve, while running back Phillip Lindsay (toe) was inactive for Sunday's game and is expected to miss another two to three weeks.

Wide receiver Courtland Sutton (knee/leg cramps), who missed the season opener with his own shoulder injury, also then left Sunday's game early in the second half. Starting defensive end Dre'Mont Jones suffered a knee injury in the second half and did not return.

"We've got a lot of guys hurt,'' said Broncos tight end Noah Fant as Risner speculated following the game with the abbreviated training camp and no on-field work in the offseason due to COVID-19 "there's going to be more injuries this year.''

The Steelers had made their defensive intentions known early in Sunday's game with plenty of pressure packages against Lock almost from Lock's first throw. Lock hit his first pass attempt of the game -- a 20-yard completion to Sutton -- but missed his next four attempts.

On the sack that finished Lock's day, the Broncos weren't able to slow down either Dupree or T.J. Watt on the play. Watt tripped Lock up in the pocket, forcing him to scramble as Dupree, who had arrived unblocked, closed in and put the hit on Lock.

"I tried to get out, tried to keep my feet,'' Lock said. "At the last second, I tried to tuck (the ball), I felt him, then fell on (the shoulder) funny.''

The Steelers simply kept the pressure on for the remainder of the day, as they had five sacks by the time the first half ended, seven sacks in the game to go with an eyebrow-raising 19 quarterback hits. At one point in the second half, Driskel had been hit on almost 50% of his dropbacks.

Driskel finished the game 18-of-34 passing for 256 yards with two touchdowns and interception. The Broncos had a chance, just inside the two-minute warning, to take a lead, but Driskel was sacked at the Steelers' 26-yard line on a fourth-and-2 play to end the comeback attempt.

"We were in an empty set ... I didn't get my eyes in the right spot,'' Driskel said of the final sack. "That was on me.''

Driskel, who was signed to a two-year, $5 million deal in the offseason to be Lock's backup, said after Sunday's game that he would be ready to play against the Tampa Bay Buccaneers if needed.