The Scotland international has spent the past seven months working under Blessin at KV Oostende, after joining the Belgians on loan from Celtic
Bottom of the Premier League following a miserable campaign, United will be in the market for a new centre-half this summer if top-flight clubs look to cherry pick their best talent when relegation is mathematically confirmed.
And, although Rhys Norrington-Davies is set to be given an opportunity to stake a claim for a first team role when his temporary agreement with Stoke City expires, that would see Hendry inevitably linked with Bramall Lane given his relationship with Blessin.
Capped five times by his country, Hendry has made nearly 30 appearances since moving to the Versluys Arena - helping Oostende climb to fifth in the table, despite languishing in 15th when competition was halted because of the Covid-19 pandemic last term.
In order to offer Blessin the chance to replace Chris Wilder, who left Bramall Lane a month ago, United must persuade the authorities he qualifies for a Governing Body Endorsement (GBE) under football’s post Brexit employment guidelines.
However Hendry is not subject to the same criteria. Born in Glasgow, he started his professional career with Partick Thistle before being signed by Wigan Athletic. After making only three appearances in Greater Manchester, he joined Dundee ahead of his switch to Parkhead.
Aged 25 and approaching the final 12 months of his contract with the former Scottish Premiership champions, Hendry’s future north of the border will be decided by whoever succeeds Neil Lennon at the helm. Eddie Howe, the former AFC Bournemouth and Burnley manager, is expected to accept the role following talks in London.
United are set to perform further due diligence on Blessin later this week, before deciding whether or not to make an official approach to Oostende who only appointed the 47-year-old last summer.
Having placed Paul Heckingbottom in caretaker charge, United face Arsenal on Sunday. They are bottom of the table and 15 points adrift of safety with only eight matches of the campaign remaining.