There was no collision that preceded the collapse, the spokesman said, but few other details were available. Cherepanov scored the first goal of the game and had eight in 15 contests this season, his third with Avangard Omsk.
"It was really kind of a surreal thing for the players," Cherepanov's agent Jay Grossman said. "He was skating in on a 2-on-1 with Jaromir and then they came back to the bench. Jaromir was talking to him and he told him he has to score on that play. The next thing you know, he collapsed.
"(Jagr) went with him into the dressing room area and they revived him for some time and then he didn't make it."
Grossman said Cherepanov was eventually taken to the hospital, but he was unable to be saved.
"I don't know the specifics, but I've heard that there wasn't an ambulance there (at the arena), that it had left, and that there were problems with the defibrillator that they had there," Grossman said. "Other than that, no details. I don't know if that would've necessarily made a difference."
The Rangers announced the death of Cherepanov shortly before they played at home against the New Jersey Devils. New York coach Tom Renney said his club was not aware of any health issues with Cherepanov.
"He's a Ranger and I think it'll have an impact on people," Renney said. "We're going to have to deal with it in our own personal way, but in the interest of a bright, young life that's over we're going to have to pursue the objective of tonight and that's get two points from New Jersey."
A pregame moment of silence was observed at Madison Square Garden as Cherepanov's picture was displayed in the midst of a black background on the center ice video board.
"The first thing we can do is honor him with a great effort tonight," Renney said.
Grossman said Cherepanov had testing at the NHL combine before last year's draft that didn't reveal any heart problems. He has been told that players in the KHL receive regular heart and blood tests, similar to those given in the NHL.
Cherepanov surprisingly slipped to the Rangers during the 2007 NHL draft and they grabbed him with the 17th pick. The talented forward dropped because of concerns about his signability and the potential difficulty in getting him to leave Russia.
"He was an exceptionally talented kid," Grossman said. "He played in the Russian Elite League, in the men's league, even before he was drafted which in and of itself is an achievement. He was a self-motivated kid that had an inner-confidence about him. A real good attitude."
New York assistant coach Mike Pelino recently returned from a one-week trip to Russia where he watched Cherepanov play and then dined with him and Jagr.
The Rangers maintained a good relationship with Omsk and the club's general manager even though there has been feuding between the NHL and Russia's KHL.
The future appeared bright for Cherepanov, and the Rangers said he definitely figured in their plans.
"I was shocked when I heard. I thought it must be a misprint or something because he just had so much going for him," Pelino said.
"He was someone who I was really excited about and thought, 'Wow, we did get something special here.' "He had things to work on. We felt he had to become a little stronger still, he had to probably become a little bit more aware defensively. But as far as raw talent went and the ability to score, he was great."
Renney kept tabs on Cherepanov every few weeks by checking in with Jagr and new Omsk coach Wayne Fleming, who recently left an assistant coaching position with the Calgary Flames to take the job in Russia.
Renney said Jagr told him that Cherepanov could probably play on New York's second line now.
"Alexei was an intelligent, energetic young man, with tremendous talent and an extremely bright future," Rangers general manager Glen Sather said in a statement. "We are extremely saddened."
