Newcastle United have suffered an injury blow with their new striker Yoane Wissa sidelined for at least another four weeks after suffering a knee injury on international duty with DR Congo, manager Eddie Howe said on Friday.

Signed for 55 million pounds ($74.26 million) following a protracted transfer saga when Brentford rejected Newcastle's initial bids, Wissa was brought in to fill the attacking void left by Alexander Isak's departure to Liverpool.

He now faces a race against time to return for Newcastle's October 18 fixture away to Brighton & Hove Albion.

"Everyone wanted Yoane to be fit," Howe told reporters ahead of Sunday's game at fourth-placed Bournemouth. "There's nothing personally I would have done differently. We did everything we did as a football club to try to look after Yoane.

"But it's like with any footballer when they go away on international duty, you're not in control of the minutes they play and, unfortunately, he gets injured and now we just have to deal the best we can with that situation.

"We think he'll be out until after the next international break. He's sort of got a race on to be fit for that Brighton game. Hopefully he can make it and then, of course, he'll be such an important player for us."

Wissa's injury setback heaps additional pressure on Newcastle's other marquee signing - Germany forward Nick Woltemade, who was signed from Stuttgart in a club-record deal worth a reported 69 million pounds.

Woltemade had a dream debut as he scored in the 1-0 Premier League win over Wolverhampton Wanderers but Howe said the 23-year-old still needed to 'acclimatise' to the Premier League.

"We're going to have to look after Nick. It's hard enough for him to come into a new league and you could see the physical effects he felt with Wolves and then the quick turnaround again here (in a 2-1 Champions league loss to Barcelona)," Howe added.

"There's no guarantee even by managing him that he's going to stay fit and play all the games, but we're going to try to give him the best chance to stay fit and also acclimatise to the league that he's in.

"But he's made a very good start. He did well when he came on (against Barca), I was really pleased with him. He was involved in the goal, so he'll hopefully be in a good place."

Newcastle's Wissa faces month on sidelines with knee injury, says Howe