Newcastle's leading goalscorer (seven) behind Swedish forward Alexander Isak (11) in the top flight this season, was taken off at half-time due to an apparent ankle injury.

Newcastle are already without mainstays Isak, Brazilian midfielder Joelinton, goalkeeper Nick Pope and others through injury.

"It looked like he (Gordon) twisted his ankle," Howe told reporters. "I wasn't sure on the incident, I didn't see what happened. But he was in a lot of pain at half-time and had to come off."

Howe said he did not know how serious the injury was. "It was sore enough for him to come off, that was his decision, he knew he couldn't continue.

"We hope it's not bad. He's such an important player for us and we missed him when he went off."

Howe also provided an update on Isak, who has missed two consecutive matches due to a groin injury.

"We don't think it's too serious. We don't yet know when he'll be back," Howe said.

Newcastle dropped to ninth place with 33 points after their draw against promoted Luton and will next visit 17th-place Nottingham Forest on Saturday.