When Sipke Hulshoff received a yellow card in Liverpool’s 2-1 victory over Wolverhampton Wanderers, fans may have been forgiven for doing a double-take.
There is nothing unusual in a referee warning a coach but in Hulshoff’s case, it was that rarest of things — a moment when Arne Slot’s No 2 was centre-stage.
Slot has publicly choreographed Liverpool’s post-Jurgen Klopp era, constantly instructing his team from the technical area while, behind him, Hulshoff watches from his seat with a clipboard rarely out of his hands.
The background is where the 49-year-old likes to be, away from outside distractions so he can focus on his job of coaching, analysing and developing — but his role as Slot’s assistant should not be downplayed. Their relationship stretches back 10 years and they have developed a strong bond based on mutual trust and a shared football philosophy. Known as a “field trainer”, Hulshoff is the vocal leader of Liverpool’s training sessions and plays a vital role in player development.
So who is the man helping Slot make the best start in Liverpool’s managerial history? The Athletic spoke to multiple sources, some of whom asked to remain anonymous to protect relationships, about his coaching style and what makes him so valued.
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Hulshoff is, in many ways, an unlikely figure to be making an impression at one of Europe’s elite clubs. His professional football background was limited so he had to build from square one.
His early years were spent coaching youngsters at Cambuur Leeuwarden and Groningen before he moved to Dutch third-tier club ONT Opeinde, where he worked under chairman Jeen Visser.
“He is a real people person and very knowledgeable. He is there when you need him to be there. He is among the players, not above them, so those players work hard for Sipke,” Visser told Dutch broadcaster Omrop Fryslan.
There were spells with lower-league sides Bergum followed by PKC’ 83, as well as a stint as a youth coach at Red Bull Ghana. He eventually became the club’s head coach before it closed its doors in 2014.
With each job, he built his knowledge, impressing colleagues with his innovation and dedication. Hard-working, organised and enthusiastic are all words frequently used to describe his approach. Another source describes him as tactically strong, someone who can shape a group’s playing style and quickly recognise problems during a match.
Hulshoff returned to Cambuur as a first-team coach in 2014 as part of a one-year internship to complete his UEFA Pro Licence coaching course. At Cambuur, he met Slot, who had recently been recruited from PEC Zwolle to become Henk de Jong’s assistant coach and work with the under-21s. They clicked immediately.
Slot arrived with a digital database of video clips — covering teams with similar principles or drawn from opposition analysis — illustrating his vision and principles to players and helping him form specific training drills.
It was a key part of the daily discussion he had with the other coaches, which included Hulshoff, De Jong and Dennis van der Ree, who was managing Cambuur’s under-21s having completed an internship alongside Hulshoff.
“Sipke is very observant, that’s how he learns,” Van der Ree, now assistant coach at Go Ahead Eagles, tells The Athletic. “He knows what Arne wants and he can coach those principles. The three of us spoke a lot, along with the other coaches, about how we see football. Sipke took in that information and learnt quickly so he could help develop drills for training that complemented Arne’s vision.
“Sipke is loyal. Arne trusts him to deliver training sessions that develop players. Sipke would lead the sessions. That was one of his top qualities.”
Slot and Hulshoff share the same work ethic and love of football, arriving early and leaving late each day. Those similarities extend to their football visions — particularly the importance of winning the ball back within three or five seconds or overloading areas of the pitch.
Once he completed his internship, there was a brief excursion to Qatar to coach Al Arabi but by November 2015, Hulshoff was back at Cambuur as a permanent first-team coach.
De Jong was sacked in February 2016 so Hulshoff took interim charge for one game before Marcel Keizer’s appointment. He departed following the club’s relegation and was replaced by Rob Maas. By mid-October, Maas was also gone so the reins were handed to Hulshoff and Slot on an interim basis. Hulshoff was named manager but in reality, Slot was in charge. Results lifted and they were given the job until the end of the campaign.
“Sipke had his Pro Licence so he was the official head coach as Arne did not have it at that point,” Harm Zeinstra, Cambuur’s starting goalkeeper at the time, tells The Athletic.
“They stepped up and immediately had a big influence. The way of playing and training was innovative and fun. High energy, high intensity and a very clear view of how to play. It was different from a lot of coaches who may want to play the same way — attacking football, pressing high — but they don’t train in that way.
Zeinstra already had a relationship with Hulshoff from their time playing and working in Cambuur’s academy. They lived near each other so Hulshoff would pick up Zeinstra and drive him to training.
“They raised the bar,” he adds. “We could instantly see the level of coaching of Arne and Sipke was a little bit more in the background, which fitted their profiles and personalities. They really complemented each other. No training session was similar to the last one. The focus was the same but there were always different exercises.”
Slot organised a supporters’ evening to educate fans on his and Hulshoff’s style of play — he spoke for hours about his tactics — and results on the pitch proved his ideas worked.
From their appointment until the end of the season, only champions VVV Venlo (62) won more points than SC Cambuur (60) in the Eerste League. A third-place finish, followed by a defeat in the promotion play-offs, was complemented by a run to the KNVB Cup semi-finals, including a victory over Ajax.
The pair were separated when Slot departed that summer to become assistant manager at AZ Alkmaar, working under John van den Brom, with Hulshoff returning to his assistant coach role under Marinus Dijkhuizen and then Rene Hake, before he finally left in 2019.
It was then that Hulshoff was able to develop another of his formative football relationships — this time with Wim Jonk, the former Dutch international midfielder who had four productive years in charge of Ajax’s academy and who first met Hulshoff on a UEFA coaching course.
When Jonk was appointed head coach of second-tier side Volendam, he made Hulshoff his assistant and the pair led the club to the brink of promotion before Covid-19 brought the season to a premature end.
Regardless, Hulshoff had taken his coaching to a new level. At Volendam, he began to work with smaller positional groups, specifically the defensive unit, including Micky Van de Ven, now at Tottenham Hotspur. Van de Ven worked with Hulshoff on heading, one-versus-one defending and defending spaces.
“With the defenders, we trained a lot with Sipke. He taught us tricks using images and on the field: how to defend well, have the right body language and not be too eager against a strong striker,” Van de Ven told De Telegraaf this year.
The chance to reunite with Slot came via the latter’s appointment as head coach at Feyenoord the following summer. Initially, he arrived to manage the under-21s but Slot was also keen to involve him in first-team preparations. Twice a week, Hulshoff would be part of the coaching staff overseeing first-team training and would lead one of those sessions.
One person The Athletic spoke to made comparisons to the former Liverpool assistant manager Pep Lijnders for their shared passion and enthusiasm on the training pitch – alongside a strong work ethic and ability to relay key principles to players. His attention to detail expands to keeping track of every training session. At previous clubs, he went as far as recording goalscorers from practice games, even small-sided ones, in a notebook.
Feyenoord finished third in the Eredivisie in Slot’s first season and were beaten finalists in the Europa Conference League. The strides forward meant Slot expanded his first-team coaching staff and Hulshoff was promoted into an assistant coach role.
His role began to expand as he continued to lead training sessions. Training was planned collectively but Hulshoff was instructed to prepare parts of the session based on the vision laid out by Slot, who took a watching brief and only jumped in when necessary.
Hulshoff continued working with individuals and small groups on the training pitch and through analysis using clips. Slot has always led meetings. At Feyenoord, before each match, he developed a gameplan with input from Marino Pusic — the current Shakhtar Donetsk manager who Slot also wanted at Liverpool — and Hulshoff, who conducted opposition analysis. Hulshoff would sometimes help present post-match debriefs. The season concluded with Feyenoord winning the Eredivisie.
Hulshoff has never sought attention. For him, media duties, which Slot handles seamlessly, are only a distraction. Lijnders was happy to step in for Klopp for pre-match Carabao Cup press conferences but Hulshoff has shown no such inclination at Liverpool.
His only focus is being on the training ground and developing players. He knows his strengths, which helps explain why he has never taken up a head coach role elsewhere, despite interest from other clubs.
His expertise on the training pitch alerted Netherlands manager Ronald Koeman, who, after a handful of conversations, brought Hulshoff onto his staff. During his first camp, in October 2022, he made an instant impression.
“You see his qualities and I like that,” Liverpool captain Virgil van Dijk told Voetbal International. “He is very clear and tactically strong. I like the moments when he leads a training session.”
His time with the Netherlands allowed him to forge not just a relationship with Van Dijk, but also Cody Gakpo and Ryan Gravenberch, who has been reinvigorated in a deeper role this season.
Hulshoff resigned from the role before the 2024 European Championship to follow Slot to Liverpool, a measure of the strength of their relationship. He may not always be a visible presence at Anfield but Hulshoff’s role in Slot’s early success should not be underestimated.
(Top photo: Nick Potts/PA Images via Getty Images)