Zeljko who? You probably don't know the name, but you certainly know the face if you have watched Jürgen Klopp in the dug-out over the last decade.
bundesliga.com turns the spotlight on a man who — unlike his friend and colleague — does not get the headlines he deserves.
1) 'Tactical mastermind'
Manchester City's Ilkay Gündogan, one of the game's most refined practitioners, acknowledged Klopp as a father figure, but hailed Buvac as "more the tactical mastermind" when they worked together at Dortmund where the blueprint for BVB's high-tempo game was drawn up by Klopp's number two. Klopp is the ringmaster of the media circus, but Buvac is no clown, and can even be a lion tamer, which will come in handy should the backpage criticism start to bite. "In the dressing room," Dortmund's former Liverpool and Real Madrid midfielder Nuri Sahin stated, "his word is law."
2) Yugo boss
That name — try it properly, Zhel-ko Boo-vatch…don't worry, you'll get it eventually — comes from former Yugoslavia where Buvac, now 56, was born on 13 September 1961. Of Bosnian-Serb descent, Buvac grew up in Omarska, which lies in modern-day Bosnia-Herzegovina.
3) Direction Deutschland!
The Balkans have been a fruitful breeding ground for silkily skilled attacking midfielders blessed with the vision for a final pass: Dragan Stojkovic, Dejan Savicevic, Robert Prosinecki, Luka Modric, Ivan Rakitic… Buvac was not of their class on the pitch, but shared their in-built understanding and reading of the game that he would put to use so effectively on the touchline. He carved out a modest career pulling strings for Borac Banja Luka before moving to Germany to join Rot-Weiss Erfurt — then in Bundesliga 2 — in 1991. After a season there came the move to Mainz that would change his — and Klopp's — life.
4) A training master, he is
The duo featured on the pitch together for three years before Buvac spent six seasons at amateur outfit Neunkirchen, the last three as coach. Klopp though never lost touch with his former team-mate, nor escaped the idea that Buvac was tailor-made to be his number two. Promotion to the Bundesliga and European qualification with Mainz, back-to-back Bundesliga titles and a UEFA Champions League final appearance with Dortmund, and now stunning success at Liverpool are proof he wasn't wrong. Though he receives the plaudits, Klopp paints the picture of himself as the Padawan and Buvac the Jedi knight. "Zeljko is a master of all forms of training. I learn from him every day," the Liverpool manager said admiringly. "Most of the time, we work together telepathically, we don't need to say anything."
5) Beginner's luck?
Bar his three years at Neunkirchen, Buvac's only other taste of being 'number one' was a brief, unfulfilled spell as coach of Republika Srpska in 2013. Scheduled to meet a FIFA Select XI in an exhibition encounter, the match never happened. His lack of frontline managerial experience may be a worry for some, but there are precedents of men being thrown in at the deep end of the dug-out, and not only swimming, but walking on water.
Julian Nagelsmann has excelled at Hoffenheim after stepping up from the youth ranks, Domenico Tedesco had less experience than Buvac when he was appointed Schalke boss last summer, and look where the Royal Blues are. Still not convinced? Well, Zinedine Zidane — having seen off Bayern Munich — is plotting a course for a third successive UEFA Champions League title at Real Madrid in his debut role at the top level. Like Buvac, the iconic Frenchman had been a number two — to Carlo Ancelotti — before stepping up.
And if Buvac does become the new man in charge at the Emirates Stadium this summer, concerned Arsenal fans should remember they — and everyone else — were scratching their heads and asking each other the same question in 1996: 'Arsene who?'