Pope, who has been ever-present for Newcastle in the Premier League this season, injured himself diving for a shot during the second half of Saturday's 1-0 win over Manchester United, and had to be replaced by Martin Dubravka.
“The situation with Nick is the disappointment of the night,” Howe told the club’s official website. “Martin comes on and manages that last period of the game really well, but mixed emotions on that front.
“It looks like a shoulder dislocation which is a serious injury, and of course very difficult for a goalkeeper to have a problem with your arms.
"We will await a specialist’s opinion and see what the next step is."
Newcastle are next in action on Thursday when they visit Everton and Howe will be looking to keep the momentum going with a high-quality performance similar to Saturday's victory over Man Utd.
"It was a massive win for us, especially off the back of Paris [Saint-Germain] and those emotions and those feelings," added Howe, whose side were stung by a penalty equaliser in the final seconds of their midweek UEFA Champions League match in France.
"It was a brilliant response from the players, one of our best performances, maybe of this season, maybe looking at last season as well.
"If you take everything into consideration, the squad is stretched, but I thought we gave a brilliant technical performance and a really good athletic performance in terms of off the ball, so I’m delighted with the players."