SEATTLE -- Seahawks wide receiver Cade Johnson was taken off the field on a stretcher and transported to Seattle's Harborview Medical Center after suffering a concussion in the team's preseason opener Thursday night at Lumen Field.

Head coach Pete Carroll said initial tests revealed no issues beyond the concussion. He did not know whether Johnson would remain hospitalized overnight.

"We got a real good report -- the early one," Carroll said. "I'm hoping that's conclusive, but that's what we heard."

He added that the team "went to the max precautions, and the findings were already really positive."

Johnson briefly appeared unstable while getting up after he was tackled on a 17-yard kickoff return about four minutes into the second quarter against the Vikings. He walked off on his own power and was taken in the medical tent for evaluation.

Johnson spent the remainder of the quarter in the tent before he was loaded onto a stretcher, with his neck stabilized, and wheeled off the field at halftime.

Johnson went undrafted out of South Dakota State in 2021 and spent parts of his first two seasons on Seattle's practice squad. He appeared in three regular-season games last year, recording two catches for 21 yards.

Also Thursday, Seahawks receiver Dee Eskridge left in the first half and didn't return after twisting his right knee. He is eligible to practice and play in preseason games before he serves a six-game suspension for violating the league's personal conduct policy.

"It's a cartilage thing," Carroll said of Eskridge. "We don't know how bad it is yet. He's getting around on it, so it's not horrible. It wasn't catastrophic, but we've got to figure out how severe it is."