Huddersfield Town winger Anthony Pilkington broke a leg in Tuesday's win over Rochdale.
The 22-year-old also dislocated his ankle and will have an operation on Thursday, although no timescale has yet been given for his recovery.
Manager Lee Clark told BBC Radio Leeds: "It was innocuous. Anthony's tried to retrieve the ball and the next thing you know it's just a horrific injury.
"It's taken the gloss off tonight, the result pales into insignificance."
He added: "It's hit everyone hard - I had a couple of my players emotionally drained with tears in their eyes and there were even a couple of lads from the opposition who were the same."
Pilkington was substituted midway through the second half of the match at the Galpharm Stadium and taken by ambulance to Huddersfield Royal Infirmary.
His ankle was reset on Tuesday night and he will go to Manchester on Thursday for an operation performed by Dr Ashok Paul, the same surgeon who operated on Premier League footballers Alan Smith and Antonio Valencia when they suffered similar injuries.
"We are a big family here and the lads are distraught for Anthony," Clark added.
"We were all very emotional and I was pleased at how hard the lads dug in and put everything to the side and picked up three points.
"They have seen a good friend, an important part of our team, pick up a horrific injury and it has taken the gloss of the night really."
Bookmark with:
What are these?