Alexis Sanchez scored 47 goals in 141 games for Barcelona but has only scored twice in 23 appearances this campaign for UnitedBBC coverage
How to follow: Listen on BBC Radio 5 live and BBC local radio; text commentary on the BBC Sport website
Alexis Sanchez and Nemanja Matic have both travelled as part of the Manchester United squad for Tuesday's Champions League quarter-final second leg against Barcelona.
Forward Sanchez has been out for six weeks with a knee injury and midfielder Matic has missed the past three games.
Both players missed last Wednesday's first leg, which Barcelona won 1-0.
Matteo Darmian has also been included in the 22-man squad after injury but Ander Herrera and Eric Bailly are out.
United are aiming to overturn a first-leg deficit for the second round in a row on Tuesday. In the last 16, they recovered a 2-0 deficit against Paris St-Germain by winning 3-1 at the Parc des Princes to go through on away goals.
MATCH FACTS Head-to-head
Barcelona have never lost a home match against Manchester United in European competition (W2 D2), with their last such meeting finishing 0-0 in April 2008.
Of the 70 previous occasions a side has won a Champions League knockout tie first leg away from home, just four have been eliminated (6%). However, two of those instances have been in this season's competition, including once by Manchester United.
In their first-leg defeat, Manchester United failed to register a single shot on target for the first time in a Champions League game since March 2005 (0-1 against AC Milan).
Barcelona have progressed from 39 of their 41 European ties in which they won the first leg away from home - the exceptions were against FC Koln in the 1980-81 UEFA Cup, and against Metz in the 1984-85 Cup Winners' Cup.
They are unbeaten in 30 Champions League home games, the longest such run of any club in the competition (W27 D3). They have also not conceded more than once in any of those 30 games (15 goals in total) since a 0-3 loss to Bayern Munich in the 2012-13 semi-finals.
Barcelona's Lionel Messi has scored 22 goals in 31 Champions League games against English opponents, more than any other player in the competition. A total of 13 of those strikes have come in his past nine appearances against English sides at the Nou Camp, including hat-tricks against Arsenal (April 2010) and Manchester City (October 2016).
Barcelona striker Luis Suarez has had more shots without finding the net than any other player in the Champions League this season (33).
Manchester United have progressed from one of their four previous European ties in which they lost the first leg at home, though it was in the last round against Paris St-Germain.
A total of 90% of Manchester United's Champions League goals this season have come away from home (nine out of 10). However, they have won just one of their past five away knockout stage games in the competition (D2 L2).
United have lost 49 Champions League games - they could become the ninth different club to reach 50 defeats in the competition, and just the second English side (Arsenal, 53).
'United have just 9% chance of progression'
Simon Gleave, head of sports analysis, Gracenote:
Given the draw, Manchester United were the outsiders of the four English clubs to reach the semi-finals prior to the first legs.
A 1-0 home defeat against Barcelona, the Euro Club Index number one team, has made United's chance even more remote and they are now given just a 9% chance of claiming a place in the last four of the Champions League.
Similarly United's chance of winning the Champions League this season has reduced to around 1%.