DETROIT -- Kerryon Johnson took the ball and exploded through the hole created by the middle of the offensive line. He showed the short-burst speed along with the instincts he has had since he arrived in Detroit as the team’s second-round pick this spring.

He cut outside, headed toward the right sideline and, 24 yards later, had another big gain. Johnson has had runs like that all season, big plays that ignite drives and are confidence-boosters for a franchise desperate for a big-time runner.

It’s why what happened later Sunday should be so concerning. Johnson left the game in the third quarter with a knee injury, and he was first deemed questionable before being downgraded to out. In a game in which the Lions got their first win in almost a month, beating the Carolina Panthers 20-19, there is some degree of angst regarding the best running back the team has had since Barry Sanders retired.

The extent of Johnson’s injury is unclear, although being ruled out in a close game is never a good sign when it comes to the health of a player. After the game, Lions coach Matt Patricia had no update, either, saying they had to wait for doctors to come back with more information.

If Johnson ends up missing time, it would decimate a Detroit running game that had shown signs of growth this season after four seasons of being ineffective. And Johnson was in the midst of a strong rookie season, one in which 1,000 yards was in reach.

“It’s huge to have an explosive guy [like Johnson], a quick guy like Theo [Riddick], a power guy like [LeGarrette Blount],” receiver Kenny Golladay said. “So it’s funny having three.”

Johnson, though, has been the complete back the Lions have been searching for, a three-down option who can run inside and outside and catch passes. Even his pass protection -- he had one particularly critical block against the Panthers before his injury -- has improved throughout the season.

Johnson’s injury came on a play that was somewhat indicative of his season, making something out of what looked like it could be nothing. Johnson took the ball and started running right. Having nothing there and everything falling apart, Johnson cut back and ran across the field all the way to the left sideline, where he was tackled.

It was a 3-yard gain on which he ran for so much more -- but what happened after might cost the Lions their most productive rusher and possibly their best offensive player.

Johnson being in the game keeps defenses from focusing too much on Detroit’s passing game -- a group that is dealing with injuries itself since starting wide receiver Marvin Jones Jr. missed this game with a knee injury for which he’s getting a second opinion.

If Johnson misses time, the Lions might have to rely more on a passing offense that is led by the team's other budding star, Golladay, who had eight catches for 113 yards and a touchdown in his first game as the obvious No. 1 option with Golden Tate traded and Jones injured. That could hurt the balance that Detroit was trying to build.

At the very least, the Lions appreciate Johnson's ability, even if they didn’t want to talk about his injury.

“He’s obviously a great runner when you hand it to him,” quarterback Matthew Stafford said. “He does a nice job out of the backfield when you throw it to him. Had a nice play on a screen here [Sunday], but he’s got some big-play ability.

“Obviously, you see it in some 20-plus runs. I’ve got the best view in the house. I’m right behind it sometimes and he splits a guy, splits a seam, and he’s out. He’s done a nice job for us, and it’s more of the same [Sunday].”

The backs behind Johnson, well, they haven’t inspired much thus far. Blount entered Sunday averaging 2.6 yards per carry and had 1 yard on seven attempts against the Panthers. Riddick has never been much of a rushing option, and Zach Zenner was just re-signed earlier this month.

Those backs could be Detroit’s immediate options in the future as they hope for good news on their rookie sensation. Until they receive that, the Lions don’t want to speculate.

“I guess we’ll have to address that when we figure out what’s going on,” receiver TJ Jones said. “But as of right now, I don’t know. Our offense has him in it, so that’s what I’m going to go off."