United announced the squad on their official website as the players flew out on Monday morning.
A knee injury has kept Sanchez out of action since March 2, while Matic has not played in April because of a muscle issue.
Despite receiving a yellow card in the first leg that has ruled him out of the second, Luke Shaw has also gone with the squad. In the last round, Paul Pogba joined his team-mates at the Parc des Princes after being sent off and suspended against Paris Saint-Germain in the first leg.
Ander Herrera and Eric Bailly are not included.
The former, who will reportedly join PSG this summer when his contract runs out, according to the BBC, has missed the Red Devils' last three games with a thigh injury,
The latter has not played for United since he came off in the first half against PSG on March 6 and later picked up a knock while on international duty.
United overturned a 2-0 deficit in that PSG clash, winning 3-1 at the Parc des Princes to secure passage to the quarter-finals.
They'll need to mount a similar comeback to progress again after Barca beat them 1-0 at Old Trafford in the first leg.
Football writer Leanne Prescott does not believe the Catalan club will be overly worried after the Red Devils' uninspiring performance against West Ham United on Saturday:
United will hope Matic can give their defence added protection if he takes part on Tuesday.
As for Sanchez, he contributed 47 goals and 35 assists in three seasons with Barcelona but has scored just five times in 41 outings for United since he joined in January last year.
The Chilean might not walk straight back into the starting lineup after his spell on the sidelines, but United could use a top performance from him if he is involved at any point.