Scott Allan is set to miss a number of matches for Hibs due to an ongoing health problem.
The midfielder is out of this Sunday's match at Easter Road against Rangers and the following Sunday's trip to Celtic Park.
Allan has played in five of Jack Ross' side's seven Premiership games this season.
The manager said: “ Scott Allan has a health issue at the moment that we are investigating further, so he’ll be out for the upcoming games.
"It’s a health issue that’s a private and confidential matter, so if and when we have more understanding of it we’ll be prepared to comment, but at the moment it rules him out for Sunday and the immediate games coming up after."
Jamie Murphy will also miss out, with the terms of the winger's loan deal meaning he's unable to face parent club Rangers.
Looking ahead to the match, Ross said: "We’ve set lofty ambitions and challenges to the players from pre-season. and they’re going the right way about meeting them.
"In some ways it is a good barometer because to get where we want to be, we need to win games like Sunday against that level of opposition.
"Rangers' form and results this season have been outstanding and the way they have dominated the ball this season makes it difficult for teams to lay a glove on them.
"But the one thing for us is that we’ve carried an attacking threat this season and we’ve played in a manner that means we have players who can be a threat in forward areas."
