Foxes boss Craig Shakespeare is hoping his captain will make a return for the second leg against the LaLiga side at the King Power Stadium
Wes Morgan has been ruled out of Leicester City's trip to Crystal Palace on Saturday and is rated at only 50/50 for their Champions League clash with Atletico Madrid on Tuesday.
Captain Morgan, an inspirational leader in the Foxes' remarkable Premier League title success last season, has not played for a month due to a back injury and will not be rushed back for the weekend meeting at Selhurst Park.
But, with relegation all but staved off following Craig Shakespeare's appointment as manager until the end of the season, overcoming a 1-0 deficit to Diego Simeone's Atletico in their last-eight tie is now the priority.