Promising Stoke midfielder Andrew Hall, 18, was held after Megan Leigh Peat was stabbed to death at a party.
Witnesses saw a teenage boy covered in blood leaving the half-term bash early on Saturday.
Last night detectives had still not begun questioning Hall over the fatal knife attack. He was being treated in hospital for injuries believed to be a near-severed finger.
The young star played this season for Stoke City’s Under-18 side and scored the goal that sent them to the fourth round of the FA Youth Cup.
Stabbed ... tragic Megan Leigh Peat
Megan died at a semi in a quiet cul-de-sac after paramedics battled in vain to save her.
The party had been thrown by a teenage boy while his parents were away on holiday.
Police, who were still awaiting the results of a post-mortem, continued to comb the scene for clues yesterday. Splatters of blood could be seen on the path.
Flowers and lanterns were left outside the house in Ampthill, Beds, by Megan’s father David and tearful pals.
His note read: “Megan Moosay, miss you more than words can say. You will always be in my thoughts and forever in my heart. Love you forever, Dad.”
Best friend Georgie Dymock, 15, said: “We had a lot in common. She was a real joker.
“She and Andrew were on and off for about ten months. They met through friends. She was well happy.” Pal Chelsie McAneny, 16, described aspiring midwife Megan as the “brightest star”.
Investigation ... cops near murder house
Neighbour Anna Bunney, 29, said: “We didn’t realise there was a party or know what had happened until the next morning.
“I heard the owners were on holiday. I think she is a nurse. I heard the son wasn’t even there and lent his keys to a friend.”
Megan’s dad and mum Nicola, both 39, from Westoning, Beds, were too distraught to speak last night. Grandmother Wendy Line struggled to hold back tears saying: “I don’t want to say anything at the moment.”
Neighbours of Andrew Hall, in nearby Flitwick, said his parents had gone to visit him.
Last night a Stoke City spokesman said: “The club are not prepared to comment at this stage other than to say that the thoughts of everyone here are with Megan’s family at this tragic time.”