McClair won a whole host of trophies during an 11-year stint with United including four Premier League titles
The Scotland international was unrecognisable in a photo taken with a supporter while sipping a pint in a Manchester pub on Monday night.
With a big, bushy white beard and long, wispy hair, McClair who was fondly nicknamed 'Choccy' stunned fans of a certain vintage who remembered him in his heyday.
Some suggested he looked like a rock star, while another wondered: “Is that actually Brian McClair? He could do with a trim.”
Someone else commented: "He here he’s there he’s got a lot of hair Brian McClair."
One fan said McClair was “probably my first childhood hero”, although another suggested: "Brian McClair became Santa Claus after retiring from football."
One other fan agreed, writing: "He deserves a pint after just coming through his busiest time of the year."
Another added: "Absolute belting bloke he had a lot of time for us younger lads."
Having started his career with Aston Villa, McClair made his name in Scotland during spells with Motherwell and Celtic.
He would eventually earn a transfer to United in 1987 where he achieved legend status, scoring 27 goals for the Red Devils.
McClair won a whole host of trophies during an 11-year stint with United including four Premier League titles.
He would also lift two FA Cups, one League Cup, five Charity Shields, the European Cup Winners' Cup and the European Super Cup.
The beloved centre-forward would also earn two Sir Matt Busby Player of the Year awards during his time at Old Trafford while earning 30 caps for his country..
McClair moved back to Motherwell for a season before officially hanging up his boots mid-way in 1999.
After retiring, McClair took on a coaching role at Blackburn Rovers before returning to United, where he spent several years as Youth Academy Director.