The 24-year-old had the operation on Wednesday, with the club hoping that he will return to training in August.
The former Ipswich Town player will miss the opening-day showdown with the Tractor Boys, while he is also expected to be missing for fixtures with Huddersfield Town and Sheffield Wednesday.
Trotter scored six goals in 42 appearances for the Lions last season.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Leicester CityLeicester | 44 | 30 | 4 | 10 | 86 | 39 | 47 | 94 |
| 2 | Leeds UnitedLeeds | 44 | 27 | 9 | 8 | 80 | 37 | 43 | 90 |
| 3 | Ipswich TownIpswich | 43 | 26 | 11 | 6 | 85 | 53 | 32 | 89 |
| 4 | Southampton | 44 | 25 | 9 | 10 | 85 | 61 | 24 | 84 |
| 5 | West Bromwich AlbionWest Brom | 44 | 20 | 12 | 12 | 67 | 44 | 23 | 72 |
| 6 | Norwich CityNorwich | 44 | 21 | 9 | 14 | 77 | 61 | 16 | 72 |
| 7 | Hull City | 44 | 19 | 12 | 13 | 65 | 56 | 9 | 69 |
| 8 | Coventry CityCoventry | 43 | 17 | 12 | 14 | 68 | 55 | 13 | 63 |
| 9 | Middlesbrough | 44 | 18 | 9 | 17 | 64 | 60 | 4 | 63 |
| 10 | Preston North EndPreston | 44 | 18 | 9 | 17 | 56 | 61 | -5 | 63 |
| 11 | Cardiff CityCardiff | 44 | 19 | 5 | 20 | 50 | 61 | -11 | 62 |
| 12 | Bristol City | 44 | 16 | 11 | 17 | 51 | 47 | 4 | 59 |
| 13 | Sunderland | 44 | 16 | 8 | 20 | 52 | 51 | 1 | 56 |
| 14 | Swansea CitySwansea | 44 | 15 | 11 | 18 | 57 | 62 | -5 | 56 |
| 15 | Watford | 44 | 12 | 17 | 15 | 59 | 58 | 1 | 53 |
| 16 | Millwall | 44 | 14 | 11 | 19 | 43 | 55 | -12 | 53 |
| 17 | Stoke CityStoke | 44 | 13 | 11 | 20 | 44 | 60 | -16 | 50 |
| 18 | Queens Park RangersQPR | 44 | 13 | 11 | 20 | 41 | 57 | -16 | 50 |
| 19 | Blackburn RoversBlackburn | 44 | 13 | 10 | 21 | 58 | 74 | -16 | 49 |
| 20 | Plymouth ArgylePlymouth | 44 | 12 | 12 | 20 | 58 | 69 | -11 | 48 |
| 21 | Sheffield WednesdaySheff Weds | 44 | 13 | 8 | 23 | 39 | 68 | -29 | 47 |
| 22 | Birmingham CityBirmingham | 44 | 12 | 10 | 22 | 48 | 64 | -16 | 46 |
| 23 | Huddersfield TownHuddersfield | 44 | 9 | 17 | 18 | 47 | 74 | -27 | 44 |
| R | Rotherham UnitedRotherham | 44 | 4 | 12 | 28 | 32 | 85 | -53 | 24 |
| > Championship Full Table | |||||||||
