Fellow players have taken to Twitter to voice their support for Fabrice Muamba after the Bolton midfielder collapsed on the field during an FA Cup tie with Tottenham on Saturday.
Bolton has said in a statement that Muamba was admitted to a heart-attack center and is critically ill in an intensive-care unit.
And the rest of the soccer world is hoping for his full recovery.
Wayne Rooney, Manchester United:Hope fabrice muamba is ok. Praying for him and his family. Still in shock.
Robin van Persie, a former teammate of Muamba at Arsenal:[I'm] so sad about what happened to Fabrice Muamba today. Played with him 4 a couple of years. What a great guy. Always a smile on his face.
Emmanuel Adebayor, Tottenham:Doesn't matter if you aren't religious........ Pray for Fabrice Muamba.
Kyle Walker, Tottenham:Doesn't matter who you support..Doesn't matter if you aren't a football fan. Doesn't matter if you aren't religious..Pray for Fabrice Muamba.
Rio Ferdinand, Manchester United:Come on Fabrice Muamba, praying for you.
Vincent Kompany, Manchester City:'Critically ill and intensive care' I really hope that this nightmare will be soon over and I wish for Fabrice Muamba to recover fully.
Kevin Prince Boateng, AC Milan:I think I speak for all the footballers in the world, we are all with you fabrice muamba!!!
Steve Nash, NBA star with the Phoenix SunsSickening feeling waiting to see if Fabrice Muamba is ok. 23 & his heart has stopped during the match. Puts everything in perspective.
Stuart Holden, Muamba's teammate at Bolton:Praying for you Fab. Hope he's OK. Thoughts with him and his family. For all those asking, I know as much as you do. Waiting anxiously for updates from teammates. Fab is a fighter!