But manager Neil Lennon revealed he would fly home with his team-mates after initially fearing the 19-year-old might have to stay in hospital in Philadelphia. Lennon estimated that the teenager might be out for up to six weeks.
"He is coming back with us which is great news," Lennon told the club's official website. "He needs a plate inserted in his jaw and I think he may made need an extraction of a tooth which has been damaged."
McGeouch was knocked unconscious in an aerial challenge with Real defender Nuri Sahin during Celtic's 2-0 defeat on Saturday before being taken to hospital in a neck brace.
Lennon added: "Thankfully, there are no neck or head injuries. It was very similar to the injury Henrik (Larsson) had when he broke his jaw against Livingston that day. So we might be looking at four to six weeks.
"Obviously it´s a blow but it could have been a lot worse and he's a young lad who will recover quicker than most. He had a stable night in hospital, and thankfully he is coming home with us today."
Lennon suffered other more minor injury worries in the trip, all among his forwards. Anthony Stokes felt ankle pain during the warm-up and dropped out of the team, Gary Hooper sat out the game after complaining of tight hamstrings and Daryl Murphy came off with a hamstring team.
An under-strength Celtic team lost against a strong Real squad who scored goals in each half from Jose Callejon and Karim Benzema.