The 19-year-old midfielder joined the League Two side at the start of the season as injury cover.
However, he played only one match for United during his time at Glanford Park.
Clark, who is a graduate of Barnsley's youth academy, spent part of the last campaign on loan at Chesterfield.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| C | Portsmouth | 45 | 27 | 13 | 5 | 76 | 41 | 35 | 94 |
| 2 | Derby CountyDerby | 45 | 27 | 8 | 10 | 76 | 37 | 39 | 89 |
| 3 | Bolton WanderersBolton | 45 | 25 | 11 | 9 | 83 | 48 | 35 | 86 |
| 4 | Peterborough UnitedPeterborough | 44 | 25 | 8 | 11 | 86 | 56 | 30 | 83 |
| 5 | Barnsley | 45 | 21 | 12 | 12 | 81 | 63 | 18 | 75 |
| 6 | Lincoln CityLincoln | 45 | 20 | 14 | 11 | 65 | 38 | 27 | 74 |
| 7 | Oxford UnitedOxford Utd | 45 | 21 | 11 | 13 | 77 | 55 | 22 | 74 |
| 8 | Blackpool | 45 | 21 | 10 | 14 | 63 | 45 | 18 | 73 |
| 9 | Stevenage | 45 | 18 | 14 | 13 | 55 | 45 | 10 | 68 |
| 10 | Leyton Orient | 45 | 17 | 11 | 17 | 50 | 54 | -4 | 62 |
| 11 | Wycombe WanderersWycombe | 44 | 16 | 13 | 15 | 58 | 54 | 4 | 61 |
| 12 | Exeter CityExeter | 45 | 17 | 10 | 18 | 45 | 59 | -14 | 61 |
| 13 | Wigan AthleticWigan | 45 | 19 | 10 | 16 | 61 | 56 | 5 | 59 |
| 14 | Northampton TownNorthampton | 45 | 17 | 8 | 20 | 56 | 65 | -9 | 59 |
| 15 | Bristol Rovers | 45 | 16 | 9 | 20 | 52 | 66 | -14 | 57 |
| 16 | Charlton AthleticCharlton | 45 | 11 | 20 | 14 | 64 | 64 | 0 | 53 |
| 17 | Reading | 45 | 15 | 11 | 19 | 65 | 68 | -3 | 50 |
| 18 | Shrewsbury TownShrewsbury | 45 | 13 | 9 | 23 | 34 | 64 | -30 | 48 |
| 19 | Cambridge UnitedCambridge | 44 | 12 | 10 | 22 | 38 | 60 | -22 | 46 |
| 20 | Burton Albion | 45 | 12 | 10 | 23 | 39 | 64 | -25 | 46 |
| 21 | Cheltenham TownCheltenham | 44 | 11 | 8 | 25 | 38 | 63 | -25 | 41 |
| R | Fleetwood TownFleetwood | 45 | 9 | 13 | 23 | 46 | 72 | -26 | 40 |
| R | Port Vale | 45 | 10 | 10 | 25 | 41 | 74 | -33 | 40 |
| R | Carlisle UnitedCarlisle | 45 | 7 | 9 | 29 | 41 | 79 | -38 | 30 |
| > League One Full Table | |||||||||
