Alexis Sanchez and Nemanja Matic are part of a 22-man Manchester United squad which has travelled to Barcelona ahead of Tuesday's Champions League quarter-final second leg.
Sanchez, who scored 47 times in 141 appearances during three seasons with Barca between 2011 and 2014, has not played since being taken off with a knee injury in United's 3-2 victory over Southampton on March 2.
Matic, who has been dealing with a muscular injury, has not played since United's 2-1 win over Watford on March 30.
Luke Shaw has also travelled with the squad, despite being suspended for the game at the Nou Camp after picking up a yellow card in last week's 1-0 defeat to the Spanish league leaders at Old Trafford.
Italian defender Matteo Darmian is also in the squad but Eric Bailly and Ander Herrera have both been left out.
United will be aiming to come from behind for the second time in a row in Europe's elite club competition, having seen off Paris Saint-Germain in the last 16 despite trailing by two goals after the first leg.