The Sierra Leone international, 28, left the English club earlier this summer.
Dumbuya's former teams include Doncaster Rovers, Crystal Palace and Portsmouth.
Partick are back in Scottish Premiership action on September 12 when they host Dundee.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Dundee UnitedDundee Utd | 36 | 22 | 9 | 5 | 73 | 23 | 50 | 75 |
| 2 | Raith Rovers | 36 | 20 | 9 | 7 | 58 | 42 | 16 | 69 |
| 3 | Partick ThistlePartick | 36 | 14 | 13 | 9 | 63 | 54 | 9 | 55 |
| 4 | AirdrieoniansAirdrieonians | 36 | 15 | 7 | 14 | 44 | 44 | 0 | 52 |
| 5 | Greenock MortonMorton | 36 | 12 | 9 | 15 | 43 | 46 | -3 | 45 |
| 6 | Dunfermline AthleticDunfermline | 36 | 11 | 12 | 13 | 43 | 48 | -5 | 45 |
| 7 | Ayr UnitedAyr | 36 | 12 | 8 | 16 | 53 | 61 | -8 | 44 |
| 8 | Queen's ParkQueen's Park | 36 | 11 | 10 | 15 | 50 | 56 | -6 | 43 |
| 9 | Inverness Caledonian ThistleInverness | 36 | 10 | 12 | 14 | 41 | 40 | 1 | 42 |
| 10 | Arbroath | 36 | 6 | 5 | 25 | 35 | 89 | -54 | 23 |
| > Scottish Championship Full Table | |||||||||
