Ulster have suffered a double injury blow after both Darren Cave and Roger Wilson were ruled out of their PRO12 fixture against Edinburgh.
Centre Cave has a calf problem while back-row Wilson is struggling with a knee issue as Ulster look to hit back after their loss to Munster.
In a further blow fly-half Paddy Jackson will miss the game due to having a weekend's break under the Irish player management programme.
Speaking to BBC Sport ahead to the game at Murrayfield, director of rugby Les Kiss thinks that Edinburgh will be tough to beat despite losing to Zebre in a shock result last week: "They are a belligerent type of team – we must match that and play the type of game we would like to."
"That was a shock result and I'm sure Edinburgh will respond.
Kiss added on his own team: "We are just not putting the killer blow in – it's not that we are not talented or work hard enough, it's just that our execution is letting us down at critical times.
"We need to be more clinical but their is no need to panic as we are just three off the top.
"On Friday night we must match Edinburgh in the forward pack and get to the point where we can hopefully put in a killer blow, stretch the scoreline and go into the break with a win."