Jim Wyatt of the Titans' official website reported that a backboard was brought out to transport Humphries while all players on the Titans sideline taking a knee. John Glennon of The Athletic provided a positive update, noting that Humphries sat up while on the board and was talking and moving.
"I don't think he's feeling great, but he's doing better than he was when he left the field," Vrabel added.
In the closing seconds of the first half with Tennessee trailing 17-7, Tannehill threw a pass to Humphries deep down the middle of the field.
Bengals safety Jessie Bates III appeared to hit Humphries in the head, and the receiver laid motionless on the field. Despite the vicious nature of the hit, Bates was not penalized.
Humphries is quarterback Ryan Tannehill's go-to slot receiver with wideouts A.J. Brown and Corey Davis primarily operating on the outside.
Entering Sunday's game, Humphries was among the Titans' most productive players in the passing game. He was second on the team with 22 receptions, fourth in receiving yardage with 219 and tied for third in receiving touchdowns with two.
The 27-year-old was an undrafted free agent out of Clemson and spent his first four NFL seasons with the Tampa Bay Buccaneers before signing a four-year deal with the Titans in free agency prior to the 2019 campaign.
After enjoying a career year in Tampa in 2018 with 76 receptions for 816 yards and five touchdowns, he followed it up with 37 catches for 374 yards and two touchdowns in 12 games for the Titans last season.
With Humphries out, Brown and Davis continued to serve as Tennessee's top two receivers for the remainder of Sunday's game. If Humphries misses time going forward, Kalif Raymond will likely see an uptick in usage.