United went ahead through Jamie Murphy, before Nicklas Helenius equalised for the hosts. But Ryan Flynn scored a stunning winner for the Blades, who went all the way to the semi-finals of the competition that year before being knocked out by Hull City after extra time at Wembley.
What happened to the Blades XI from that day at Villa Park?
Made over 100 appearances for the United first-team before leaving in 2018, to join Hull on a permanent basis
Right-back McMahon played over 60 times for United after arriving from Middlesbrough. He later played for clubs including Blackpool and Bradford City and is still playing at 34, after signing for National League North side Darlington late last year
Came through United's youth academy and was a mainstay of United's side during his time at Bramall Lane before being sold to Hull. Later moved to Leicester before a world-record £80m move to Manchester United. Now captains the Red Devils and is a regular for the England side, too
Spent five years at Bramall Lane and made over 200 appearances before cancelling his contract by mutual consent in 2011 to join Tampa Bay Rowdies. Is now the head coach of the USL Championship side
Hill played almost 100 times for United before spells at Tranmere Rovers and Bradford Park Avenue. Became involved with a football academy after leaving the Blades
The former Liverpool trainee joined United from Falkirk in his native Scotland and was a key member of the side that reached the FA Cup semi-final in 2014. After leaving United he went to Oldham before returning north of the border and joining St. Mirren
The Irishman played over 200 games for the Blades in the middle of midfield, captaining them to the semi-finals of both the FA Cup and League Cup during his time at Bramall Lane. Now 38, he is currently at Notts County
The older brother of Aston Villa midfielder, and former Blades target, John McGinn, Stephen is still only 32 years old but his second spell at his first club, St Mirren, came to an end in June. In September he signed for Hibernian
Another Scottish star in United's ranks, Murphy was transformed into a striker from a winger under Clough before moving to Brighton to further his hopes of winning a Scotland cap. Later moved to his boyhood club Rangers but suffered a bad knee injury and now plays for Hibernian
The striker scored two goals in injury time against Forest that season as United eventually lost 5-3 in the semi-final to Hull at Wembley. Still playing with Crewe
The mercurial Baxter arrived at Bramall Lane from Oldham, but his time at United ended after he was twice banned for failing drugs tests. He was given a second chance by Everton after his second ban and last year, signed for American side Memphis 901 FC
Took over with United in relegation trouble and led them to the brink of the play-offs, reaching the FA Cup semi-final for good measure. Was then sacked after losing in the play-offs and League Cup semi-finals. Left Burton Albion last year before taking over at Mansfield Town