The Premier League champions have been in negotiations with the Portuguese side since late November, according to The Telegraph.
Despite having a release clause of £38m, United are not expected to pay that figure.
The 23-year-old Argentinian would be likely to move to Old Trafford next summer.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Liverpool | 29 | 21 | 7 | 1 | 69 | 27 | 42 | 70 |
| 2 | Arsenal | 29 | 16 | 10 | 3 | 53 | 24 | 29 | 58 |
| 3 | Nottingham ForestNott'm Forest | 29 | 16 | 6 | 7 | 49 | 35 | 14 | 54 |
| 4 | Chelsea | 29 | 14 | 7 | 8 | 53 | 37 | 16 | 49 |
| 5 | Manchester CityMan City | 29 | 14 | 6 | 9 | 55 | 40 | 15 | 48 |
| 6 | Newcastle UnitedNewcastle | 28 | 14 | 5 | 9 | 47 | 38 | 9 | 47 |
| 7 | Brighton & Hove AlbionBrighton | 29 | 12 | 11 | 6 | 48 | 42 | 6 | 47 |
| 8 | Fulham | 29 | 12 | 9 | 8 | 43 | 38 | 5 | 45 |
| 9 | Aston Villa | 29 | 12 | 9 | 8 | 41 | 45 | -4 | 45 |
| 10 | Bournemouth | 29 | 12 | 8 | 9 | 48 | 36 | 12 | 44 |
| 11 | Brentford | 29 | 12 | 5 | 12 | 50 | 45 | 5 | 41 |
| 12 | Crystal Palace | 28 | 10 | 9 | 9 | 36 | 33 | 3 | 39 |
| 13 | Manchester UnitedMan Utd | 29 | 10 | 7 | 12 | 37 | 40 | -3 | 37 |
| 14 | Tottenham HotspurSpurs | 29 | 10 | 4 | 15 | 55 | 43 | 12 | 34 |
| 15 | Everton | 29 | 7 | 13 | 9 | 32 | 36 | -4 | 34 |
| 16 | West Ham UnitedWest Ham | 29 | 9 | 7 | 13 | 33 | 49 | -16 | 34 |
| 17 | Wolverhampton WanderersWolves | 29 | 7 | 5 | 17 | 40 | 58 | -18 | 26 |
| 18 | Ipswich TownIpswich | 29 | 3 | 8 | 18 | 28 | 62 | -34 | 17 |
| 19 | Leicester CityLeicester | 29 | 4 | 5 | 20 | 25 | 65 | -40 | 17 |
| 20 | Southampton | 29 | 2 | 3 | 24 | 21 | 70 | -49 | 9 |
| > Premier League Full Table | |||||||||
