San Francisco 49ers CEO Jed York took to Twitter and apologized to his fans after Thursday night’s 19-3 blowout loss to the Seattle Seahawks.

“Thank you #49ersfaithful for coming out strong tonight,” York wrote. “This performance wasn’t acceptable. I apologize for that.”

After the game — which dropped the 49ers to 7-5 and in danger of making the postseason — head coach Jim Harbaugh was asked about York’s comments.

“I don’t know about tweets,” Harbaugh said. “We will do what we have to do as a football team. Set our jaw to doing that.”

Players in the 49ers’ locker room were told by reporters about York’s criticism.

“It’s not acceptable,” 49ers quarterback Colin Kaepernick said of the team’s play. “We didn’t play well, we didn’t perform well. We have a much higher standard for ourselves.”

Kaepernick was only 16 of 29 for 121 yards and two interceptions. He was sacked four times and his 36.7 passer rating was a season low.

Tight end Vernon Davis, who caught two passes for 13 yards, was asked about York’s tweet.

“If he said that, then I guess it was, I guess it was unacceptable,” Davis said. “We all hold ourselves accountable around here. We’re all in it together — the owners, the coaches, the players. We’re all in it together. We can play better than that — we know it. Everyone knows it. But we didn’t go out there and do it today.

“It was unacceptable, by all of us. So we have to get back and put it all together, stay together as a team, as one, and just stay positive.”