Paramedics and both teams' medical staff rushed to treat John after he collapsed.
John Fleck is in the hospital after collapsing during the game.
Fleck was taken off on a stretcher in the second half after he received a lot of treatment.
The team-mates quickly waved medics on after the Scotland international went down.
"Fleck is conscious and in good health in the hospital." Slavisa Jokanovic told the radio that he would be okay.
The match was stopped for more than 10 minutes and Fleck was taken to the hospital.
Jokanovic didn't see what happened. He fell down. It was a complicated situation.
He asked for the result while in the hospital. We hope everything goes well with him.
It's hard for the players to focus on the moment after. The team is fighting well and we are not afraid of our weaknesses. We were trying to get three points.
The only goal of the game was scored early in the second half and Fleck needed treatment.
Enda Stevens was the first to get the attention of the referee, who stopped the game and allowed both teams' medics and the stadium's on-duty paramedics onto the pitch.
After the game, the club confirmed that Fleck received "urgent medical care" on the pitch before being taken to a waiting ambulance. At one point he stood up wearing an oxygen mask and both sets of supporters applauded before he was taken off the pitch on a stretcher.
After 13 minutes were added on at the end of the second half, the Blades were able to hold on for their first win in five games.
"It's terrible when something like that happens on the field," said the scorer. The main thing tonight is that he's stable.
It happens so fast. You expect to play a normal football match. You don't think about that when you're playing games.
