The Slovakia international formed an integral part of the Dutchman's defence during their time together in Rotterdam, while he also excelled for his nation at Euro 2024.
Occupying a left-back role at the tournament, Hancko started all four games for the Falcons, making a wonderful goal-line clearance in his nation's shock group-stage win over Belgium en route to the last 16.
Hancko also did a number on Bukayo Saka for the majority of the weekend's knockout match with England, where Slovakia were on the verge of eliminating Gareth Southgate's men before succumbing to a sensational Three Lions comeback.
With Slovakia now heading home, speculation over Hancko's future will no doubt ramp up once more, as the 26-year-old has inevitably been tipped to follow Slot to Liverpool following their successful partnership at Feyenoord.
Hancko: 'Liverpool are not looking for someone in my position
The Reds have been tipped to bolster their central defensive ranks this summer, and Hancko's ability to play on the left could also help to solve the Andrew Robertson and Kostas Tsimikas conundrums.
Robertson is now in his 30s, has been struggling with injuries in recent times and is only under contract until 2026, while Tsimikas might be allowed to leave for the right price this summer.
However, speaking to Voetbal International - as quoted by the Evening Standard - Hancko has conceded that a switch to Anfield is unlikely, despite holding talks with Slot, as Liverpool are focused on improving other areas of the pitch.
"I think that in three years he will be among the best coaches in the world," Hancko said of Slot. "I can see that happening, because I know what he did with us and now he has the biggest platform to show that.
"I have a lot of confidence in him and his staff, and I don't say that because I hope to go with him to Liverpool, because that is unlikely. I have spoken to him a few times since the end of the season, but I don't think they are looking for a player in my position, so I don't think a transfer to Liverpool will happen. But I wish him the best of luck, he really is a fantastic coach."
Hancko has proven himself to be a potent threat in the opposition box for both club and country, coming up with 11 goals and eight assists in 93 games for Feyenoord, winning the Eredivisie in his debut campaign.
The Slovakia international had a direct hand in 10 goals - seven of his own and three assists - in 48 matches last season, but his wife has also played down talk of a possible switch to Anfield.
What positions are Liverpool targeting this summer?
Despite frequent talk of a new centre-back arriving at Anfiel to replace Joel Matip, Slot is seemingly content with Virgil van Dijk, Ibrahima Konate and Jarell Quansah as his options, while Joe Gomez can also fill in if required.
Instead, the Reds are thought to be after another midfielder - specifically a defensive one - despite last summer's rebuild, in addition to a new winger amid concerns over Mohamed Salah and Luis Diaz's futures.
Furthermore, Slot is also likely to need another goalkeeper, as Adrian has left on a free transfer, and Caoimhin Kelleher could follow him out of the door for the right price as he pines for regular first-team football.