Now the former Pompey left-back is seeking a fresh challenge, following his Kilmarnock departure.
Following 57 appearances over five seasons, Haunstrup elected to leave his home-town club in favour of a free transfer to Scotland, with rules dictating compensation was not required.
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Subsequently, he established himself in Kilmarnock’s side during an eventful two years in a move he would no doubt consider a success.
In total, Haunstrup made 58 appearances and netted once, albeit with his time at Rugby Park hampered by injury.
Indeed, the 25-year-old missed their final 13 matches of the season after collecting a calf injury against Ayr in February.
That sidelined him from a title charge which saw Derek McInnes’ men finish top of the Championship, two points clear of Arbroath.
Nonetheless, Haunstrup had been a regular left-back choice until that point, racking up 17 league starts during their successful 2021-22 campaign.
However, boss McInnes has opted to release the lad from Waterlooville ahead of their return to the Scottish Premiership.
He leaves along with Stephen McGinn, Jason Naismith, Tomas Bringley and Euan Deveney, with only McGinn playing more league games this term.
At least Haunstrup departs on a high, having suffered relegation in his maiden Killie season following play-off defeat to Dundee, ending 28 years in the Scottish Premiership.
The defender emerged through Pompey’s Academy to make his debut in August 2015, lining-up against Championship Derby in the Capital One Cup.
The outcome was a 2-1 triumph for Paul Cook’s side, with goals from debutant Adam McGurk and substitute Conor Chaplin.
Haunstrup operated as a left-back understudy to Enda Stevens and then Lee Brown, eventually becoming frustrated over his lack of a consistent first-team run.
His final Pompey outing was in a Leasing.com Trophy 2-1 victory over Scunthorpe in January 2020.
Since becoming a free agent, Haunstrup has reportedly captured the interest of League One and League Two clubs.
Certainly he returns to England with his stock higher than when he departed in the summer of 2020.
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