Sheffield Wednesday and Preston have also been linked with the 22-year-old, who has made 24 appearances in League Two this season.
What’s your understanding of Kokli’s situation?
Sunderland's estimated worth following promotion to the Championship plus Kyril Louis-Dreyfus' financial dilemma
Sunderland AFC transfer news: Black Cats to pay Scottish club five-figure sum following promotion as ex-star becomes free agent
The 14 Sunderland players contracted for the Black Cats' 2022/23 Championship battle
Sunderland AFC news: Black Cats star admits he will 'probably leave' club following promotion to Championship - exclusive
Championship promotion odds: Sunderland's surprising price to go up to Premier League compared to Middlesbrough and Sheffield United
JH: “There has been interest in Ali Koiki from a few clubs this month but as of last week Northampton had not received anything concrete.
"His contract expires in the summer but the club do have an option to extend it for another year, which they will almost certainly trigger, either to get more money or to keep him longer.
"He's become an important player this season after joining as a free agent but every player has his price and I expect they would sell for the right fee.”
What type of player is he and what are his main strengths?
JH: “He's a powerful, attacking full-back that loves to get forward and support attacks.
"His barnstorming forward runs down the left flank have become a feature of the season. He's a little raw and still learning his trade as a defender but he's improved as the season has gone on.”
Is he primarily a left-back or has he played in other positions?
JH: “He's mostly played at left-back since joining Northampton, with the occasional outing at wing-back.
"He could probably do a job as an out-and-out winger as well but the advantage of playing at full-back is that he has space to run into.
"He might get a bit crowded out if played higher up.”
Do you think he could make the step up to League One?
JH: “He's only 22 and still relatively inexperienced so he has a high ceiling and could definitely make the adjustment to playing in League One in time.
"It might take some patience because he's not the finished article but all the raw ingredients are there to be a successful attacking full-back in the third tier.”
A message from the Football Clubs Editor