Matthias Jaissle hopes Anthony Elanga's injury is "not that serious" as Newcastle prepare to face Hull City on Saturday.
The 24-year-old winger was not included in the matchday squad for Monday's game against Leeds United, which saw Newcastle fall to a 4-1 defeat at Elland Road.
Up next is a test against high-flying Hull at St James' Park and Jaissle is hoping a scan will provide more clarity on Elanga's situation.
"Still not a real update on Anthony. I just spoke with him now. I think in the next 30 minutes he's in the MRI, so we'll get more clarity then and we hope that it's not that serious," Jaissle said.
"It's sad after that great start he had, the team had. We counted on him, definitely, and the way we want to play, it's a key strength in our squad. But we want to stay positive also when he's out.
"Unfortunately then we need to solve it differently, we have the ability in the squad also to adjust things. We believe in our players, we count on the others and that's always a chance for the others."
With the extent of Elanga's issue unknown, there is competition for a spot on the right wing, where Jacob Murphy started on Monday.
However, when posed with the possibility that Amar Dedic could push further up, Jaissle revealed the full-back will also be sidelined for Saturday.
"I have some thoughts on that, but Jacob was doing good," he said.
"Murphy's an experienced player, he's played that role many times. He's also intelligent to know exactly what the gaffer is demanding from him and from him on that position in particular.
"There are other options, not too many at the moment as Amar will be also not available to play on Saturday. So it's getting shorter and shorter the list."
Dedic's absence adds to Newcastle's growing injury concerns as Jacob Ramsey is also set to miss out and Jaissle confirmed he is not expecting any of his currently sidelined players to return for Hull.
- All 20 Premier League teams ranked: Which managers will be fired first?
- Man United target Lewis Hall signs new contract at Newcastle: 'Absolutely delighted'
- Premier League clubs are overspending on wingers who can't score goals
Nico González is also not involved on Saturday having been forced off in the 19th minute of the Leeds match after being hit in the head with the ball.
Speaking about Gonzalez, Jaissle said: "It was just unlucky. It was not a big hit but the hit was strong enough and precise enough to knock him out.
"Like I said also in the post-match press conference, we need to be smart.
"We have the responsibility then to follow the protocol from the league, which I really think it's so good that we are so advanced in that approach.
"He's missing Saturday's match but he's feeling much better. He's fine, usually he could train, he can progress but, again, we take that seriously that protocol. Therefore he will be out."
