Revealed: Football manager who died mid-match, leaving players in disbelief on the pitch, 'complained about his fish lunch' hours before heart attack - as devastated star speaks out

The football manager who died from a heart attack midway through a match in Serbia was complaining about the fish he ate for lunch just hours before the tragedy, a player at his club has revealed.

Mladen Zizovic, 44, collapsed on the side of the pitch 22 minutes into Radnicki 1923's match against Mladost on Sunday evening — and later passed away after being rushed to hospital. 

The match, which was initially suspended when Zizovic collapsed and then later restarted by the referee, was abandoned entirely just before half-time after confirmation of his tragic death was relayed to the players and coaching staff. 

Heartbreaking footage of the incident was shared to social media on Monday, showing players and staff breaking down in tears and attempting to comfort each other. 

Radnicki 1923 star Mehmed Cosic, who was on the pitch at the time, has since revealed that Zizovic was complaining about feeling unwell shortly before the heart attack.

The Bosnian manager, who was taking charge of just his third game at the top-flight Serbian outfit following his appointment on October 23, complained about his fish and refused to eat any more of it during the team's lunch together, according to Cosic.

'I didn't fall asleep until almost 3.30am. I have no words, we are stunned,' Cosic told Faktor as he opened up on the harrowing incident.

'I'm replaying the movie in my head. He was giving me instructions, turned around and at one point I saw that he was talking to the referee by the benches. Then he went towards our bench, turned to the others and said "I'm not feeling well, I'm not feeling well". 

'He fell, you saw everything else. In the video that appeared on social networks, you can also hear screams.

'They say he complained about the fish, said he wouldn't eat it anymore. That's what he was talking about. There were no problems during the warm-up, the game started, everything was ok. 

'We continued the game, hoping that the worst wouldn't happen and that he would be with us again. It was clear that that wasn't it, but we said that we were playing for him and that we wanted to reward him with a victory. We weren't focused, we were in disbelief, but we didn't want to disappoint him.

'We believed that he would come back and be with us again, and that we would celebrate the victory. Then there was complete shock. The referee suddenly stopped the game. Someone said "he died". Everything stopped in an instant.'

The player went on to reveal that Radnicki 1923's players and staff have been given the week off from training to mourn, with next weekend's clash against Cukaricki now postponed.

The funeral has been scheduled for Thursday, while fans of his old team FK Borac Banja Luka have already paid tribute by painting a mural of their former manager outside the club's stadium.

The Bosnian club, who were coached by Zizovic in Europe last season, were among those to pen emotional tributes to the manager as world football were plunged into mourning.

‘Boss, Our Ziza, We can't believe that you left us,' the Borac squad said.

‘We are shaken by the terrible news that reached us at Platanova 6 and we refuse to admit that we will no longer see you smiling, that we will no longer hear you making jokes at your own expense and that of others, that we will no longer listen to you talk about the football you gave your life to.

‘You left us at the age of 44, and we can only remember every moment you spent at the City Stadium. First as a player, and then as a coach who achieved the greatest European success in our history.

‘We will remember that you gave your best to Borca and Banja Luka and that together we wrote stories for eternity.

‘It's hard to admit that you're gone. Life is cruel and takes the best of us too soon.

‘It remains for us that you live through us and that we pass on the story of Mladen Zizovic, a man, a husband, a father, a brother, a son, a coach and a football player.

‘Young man, may your glory be eternal, Banjaluka and Borac will forever remember you.’ 

Radnicki 1923 also issued a tribute to Zizovic in a statement, expressing their 'deep pain and disbelief' of his passing.

‘A man who left a deep mark wherever he worked with his knowledge, calmness and nobility,' the statement read.

‘Although he spent a short time in Kragujevac, he managed to gain the respect of everyone at the club, among players, associates and fans, with his energy, professionalism and human qualities.

‘FK Radnički 1923 expresses its deepest condolences to the family, friends and everyone who knew Mladen.

'His dedication to football, passion for the game, and human warmth will forever remain etched in the memories of all who had the honor of knowing him.

‘Rest in peace, Mladen.’

Zizovic made two appearances for the Bosnia and Herzegovina national team, having spent all of his career in either his homeland or Albania.