Aside from a year-long loan spell at Scunthorpe in 2021-22, Hackney has spent his entire career at Middlesbrough, joining the club's academy at Under-10s level before working his way through their youth system and making his senior debut in January 2021.
Hackney, primarily a defensive midfielder, has made a total of 61 first-team appearances for Boro in all competitions, scoring four times and providing five assists.
The 21-year-old has established himself as a first-team regular under head coach Michael Carrick this season, as he has played the full 90 minutes in 16 Championship matches this season as well as featured in four EFL Cup ties from the start.
Hackney is also rated highly at international level having earned five caps for England's Under-21s, including his debut in September.
The midfielder is under contract at the Riverside Stadium until the summer of 2027, but a number of top English clubs are believed to be keeping a close eye on his development, sparking speculation over a possible future move.
According to the Daily Mail, Man United, Man City, Tottenham Hotspur and Liverpool are among the clubs who have sent scouts to watch Hackney, while Nottingham Forest have also been credited with an interest.
The report adds that Spurs representatives attended Middlesbrough's second-tier clash with Bristol City last month before Hackney sustained a hamstring injury, which has ruled him out of the last four games.
Sources claim that Liverpool could look to rival Spurs for the midfielder's signature, while Man United are said to be 'more keen' than Man City in signing the youngster at this stage.
Despite interest from the Premier League, it is understood that Hackney would prefer to remain at Middlesbrough until the end of the season when he expects several offers to arrive.
Boro are said to be relaxed over Hackney's future at present and will likely command a substantial fee for one of their brightest prospects.
However, there is an acceptance from the Championship club that they may be forced to part ways with the youngster if they fail to secure promotion to the top flight this season.
Hackney, who missed Middlesbrough's 2-1 home defeat to Hull City on Wednesday, is hoping to recover from his injury and return to first-team action before the end of this month.