Gronnemark's success in sport is not limited to football either. Before turning to football coaching professionally, Gronnemark tells TribalFootball.com exclusively that, in the mid-1900s, I changed sport (from amateur football) to athletics, and I was doing the 100m, 200m and 400m and I was also Danish champion in these categories. With my team, we won the European championship in Paris in 2000."
After success as an athlete, Gronnemark was part of his nation's bobsled team, where he discovered his ability to launch long throw-ins. He explains: I was part of the Danish bobsled team and when we were playing an indoor football match against Germany, I made a long throw-in and at that moment I thought If I can make it the others can too."
Gronnemark began perfecting his, and then other teams' craft. He says: After six months, I started my throw-in course. In the beginning, I worked at Viborg and FC Midtjylland only as a long throw-in coach and those teams got a lot better in this aspect.
"There is no league that is difficult for me because I am always tailor-making my throw-in tactics for any place I am."
How did he help improve these sides?
I was analysing a match on TV; I realised that a team always lost the ball in the middle of the pitch due to this. I started to work on my long, fast, and clinical throw-in that also involves the players' movement, positioning and running. I have been a throw-in coach for 20 years."
With over two decades of experience, Gronnemark now wants to expand his services through his own academy. He describes: "For the moment I am working with two things, The first is my job as a coach around the world and the second part is my online academy. It has been a great success. This project has taken part in more than 30 countries from four continents."
How does the course work?
This course is primarily for amateur and youth coaches who can't afford to invite me. Of course, professional coaches can buy it but it is tailor-made for amateur and youth coaches. Also, I have been invited around the world to talk about innovation, I have spoken at Harvard University, Boston MIT, Stockholm. I am doing different things and working on different projects."
Gronnemark has been keen on working on a freelance basis, rather than in a permanent role. This has allowed him far greater flexibility and brought tremendous success.
Arguably his most well-known work came at Liverpool alongside Jurgen Klopp. The throw-in specialist describes his experience at the club as his 'best experience' as they won seven trophies in five years.
What is it like working with the German coach?
"Klopp's a fantastic guy to work with, of course, he is funny, he is ambitious and he is also a really good listener. He gives his collaborator responsibilities and he isn't the only person who talks but allows the others also to talk."
Gronnemark expands: During my time there I was free to organise the training session as I would prefer, always coordinating with him and his staff but he never got in the middle of my session and was never obligated to do things or change things. Jurgen is good at trusting his staff, trusting his players and that's one of the reasons why people love him. So, I loved all my five years with Klopp and at Liverpool."
Klopp will be departing the Reds at the end of the season, and Gronnemark emphasises the impressive job Klopp has done at the club.
It is a decision that Klopp had all the right to take and of course, for the fans, it's very hard to accept it," Gronnemark says. The club has a difficult job of finding a really good manager and I am sure they will do. All the community there will miss Jurgen, and I am proud to have worked with him and to have won seven titles with him."
Gronnemark had a significant impact on helping Liverpool be so successful. He helped transform the throw-ins of the club's dynamic full-back pairing into lethal assets.
He explains: "The most dangerous throwers were Andy Robertson and Trent Alexander-Arnold. They were fantastic and not only about the throw-in precision but also about seeing spaces and making the right decisions."
Gronnemark also is keen to highlight another strong throw-in taker during his spell at FC Midtjylland. At the club, we scored 35 goals from long throw-ins and 34 of these 35 goals were assisted by Kian Hansen. Assisting 34 goals by a long throw-in is pretty good," he says.
He is grateful for his time at Liverpool which helped me to get my international breakthrough. When Klopp called me, it helped me a lot. I have been part of 14 different titles in 14 different teams and I have had many good experiences like in the US, in Mexico, the Mexican national team, Turkey, Germany, Belgium, Netherlands, France and Brazil."
Gronnemark chooses to work on a purely freelance basis, which enables him to take his specialist coaching around the world.
I have heard it from a lot of people saying that it is better to work full time. When I was part of Liverpool, people were asking if it would be better to be full-time there, and I said 'Yes, of course and the throw-ins would be of course better working their full time but I like the freelance work.'"
Part of the reason for this is to allow for flexibility. I can travel to many different countries and I can help more players, coaches and clubs to become better in this aspect of the game," Gronnemark says. If I were full-time in one club it would limit my knowledge and also less people would benefit from and learn from my knowledge."
What does he want to achieve in football?
My biggest dream is to change the football world regarding the throw-in situation from all levels from the amateur to the professional ones, and also for the fans, this is better because it makes the game more entertaining for them."
As a freelancer, Gronnemark was not tied solely to Liverpool. He says: When I was at Liverpool, I wasn't full-time there. It is important for me to say that in the last six years, I have coached between 8-10 professional teams or national teams around the world."
Gronnemark is not swayed by the size or reputation of a club rather which side wants to learn from him. When I accept an offer, I don't look at who is the coach or whatever but I am interested in if they are serious, if they want to get better in this aspect, and in the end in a contract is also the economical aspect too," he explains.
This attitude saw him leave Liverpool to go to Brentford. He tells how, Brentford came to me again and asked if I could help them again because they needed to get better at throw-ins and their results got much better.
For me it's not about the name of the club, I am more than happy to help any club in the world to get better in this aspect of the game."
At Brentford, Gronnemark worked with Ivan Toney. The striker was hugely important at winning the ball from throw-ins, the coach explains. Toney is a great striker and very strong physically. He is a great plus for us in these situations because he can protect the ball very well and also can run to get the ball."
Gronnemark also worked alongside his compatriot Thomas Frank at Brentford. What is he like to deal with?
Frank is a great guy, really great to work with, really positive, and a good listener too. And he is structured in his training and coaching, so he is one of the key aspects because Brentford has performed so well in the last years."
Who else has Gronnemark worked with?
I have worked with a number of important managers including Erik Ten Hag at Ajax and Ralf Rangnick. I don't like to compare people too much because I think everyone is different from the others."
With the European Championships around the corner, will any nations be seeking the services of Gronnemark?
"There are always some people contacting me about this. Let's see if I will coach any team in the Euros, all teams are welcome to contact me for the Olympics in France too. No matter from what team or what country I am open to helping them, also from the Olympics I am open to work because I know that I can make a big difference also for the national teams."
Gronnemark stops short of picking one favourite for the tournament this summer, but expects at least one surprise. He explains: "I think the favourites are the usual teams like France, Spain, England, Germany who play at home so maybe that can be a factor which can help them.
I think in these tournaments like the Euros or World Cup there will always be a surprise, it's just really hard for me to say who it may be this time. There are also different quite good teams in Europe who may go all the way to the semi-final or final so just let's wait and see who may be this time."
- adapted by Jack McRae