He now faces a race against time if he wants to be considered for Tuesday's crucial match.
"He hasn't trained yet," Holland told reporters. "But that doesn't definitely rule him out of the game on Tuesday.
"Normal procedure is that you wouldn't ask a player to play in a game without some training beforehand, so he's got to train with the group in the next couple of days.
"He's obviously close but it's day-by-day at the moment."
Chelsea will play the first leg of the tie away from home, in Madrid on Tuesday evening.