Steelers quarterback Kenny Pickett entered the NFL concussion protocol after suffering a blow to the head early in Pittsburgh's loss to the Baltimore Ravens on Sunday.

It was the second time this season that rookie Pickett has been put in the protocol, after also leaving a game against Tampa Bay in October.

Pickett was sacked by Roquan Smith on the Steelers' opening drive against the Ravens.

The 24-year-old left the field for concussion checks before being reintroduced for the Steelers' second drive. However, that drive marked the end of his involvement as he was then withdrawn.

Steelers coach Mike Tomlin looked to explain the move to briefly bring Pickett back into the action but said he did not know "about the sequence or the details".

Speaking after the game, Tomlin said: "Kenny is being evaluated for concussion, he's in the protocol.

"I think when he became symptomatic he was pulled from the game and evaluated for concussion.

"I don't know about the sequence or the details regarding the sequence."

Mitch Trubisky took over from Pickett and completed 22 of 30 passes for 276 yards with one touchdown and three interceptions, as the Steelers suffered a 16-14 defeat to slip to 5-8 for the season.

Trubisky also spoke about Pickett's blow to the head, saying: "I just kept asking him how he was feeling. He said he was feeling fine, and that was that."