The John Quinn-trained Prix Morny winner, owned by Al Shaqab Racing and between a 14-1 and 25-1 shot for the first Classic of the season, has suffered a setback.
The owners' spokesman Harry Herbert told the Racing Post on Wednesday: "The horse won't run in the Guineas. He has sustained an injury that is being assessed.
"It's awful for the sheikh [Joaan Al Thani] and for John because the horse was training the house down and would have carried the first colours."
The Wow Signal was a general 25-1 for the 2,000 Guineas. Al Shaqab are still due to be represented by Moheet, the mount of retained rider Frankie Dettori, who is a best-priced 33-1.
Highland Reel, who had been between an 8-1 and 16-1 shot, is also no longer in the mix and is an intended runner in the Poule d'Essai des Poulains [French 2,000 Guineas] on Sunday week.
Speaking by telephone to a Guineas preview media event at Newmarket on Wednesday, Aidan O'Brien said: "Highland Reel won't run as we're looking towards the French 2,000 Guineas with him."
