The 27-year-old scored 82 goals in 138 games for the Bhoys, before signing for Norwich City two years ago.
He has struggled to find the same form at Norwich though, with just 13 goals in 37 appearances, and could be on his way back to Glasgow temporarily.
Celtic have already signed striker Nadir Ciftci this summer, but Anthony Stokes has been linked with a move away from the club.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| Championship Group | |||||||||
| 1 | Celtic | 3 | 3 | 0 | 0 | 87 | 28 | 59 | 87 |
| 2 | RangersRangers | 3 | 2 | 0 | 1 | 79 | 27 | 52 | 81 |
| 3 | Hearts | 3 | 1 | 1 | 1 | 49 | 37 | 12 | 66 |
| 4 | Kilmarnock | 3 | 1 | 1 | 1 | 45 | 38 | 7 | 55 |
| 5 | St Mirren | 3 | 1 | 0 | 2 | 42 | 47 | -5 | 46 |
| 6 | Dundee | 3 | 0 | 0 | 3 | 46 | 62 | -16 | 41 |
| Relegation Group | |||||||||
| 1 | Aberdeen | 3 | 3 | 0 | 0 | 41 | 49 | -8 | 44 |
| 2 | Motherwell | 3 | 2 | 0 | 1 | 55 | 54 | 1 | 43 |
| 3 | Hibernian | 3 | 1 | 0 | 2 | 48 | 58 | -10 | 42 |
| 4 | Ross County | 3 | 1 | 0 | 2 | 35 | 64 | -29 | 33 |
| 5 | St Johnstone | 3 | 0 | 0 | 3 | 26 | 52 | -26 | 31 |
| R | Livingston | 3 | 2 | 0 | 1 | 27 | 64 | -37 | 24 |
| First Phase | |||||||||
| 1 | Celtic | 33 | 24 | 6 | 3 | 80 | 26 | 54 | 78 |
| 2 | RangersRangers | 33 | 24 | 3 | 6 | 72 | 23 | 49 | 75 |
| 3 | Hearts | 33 | 19 | 5 | 9 | 46 | 34 | 12 | 62 |
| 4 | Kilmarnock | 33 | 13 | 12 | 8 | 43 | 34 | 9 | 51 |
| 5 | St Mirren | 33 | 12 | 7 | 14 | 38 | 43 | -5 | 43 |
| 6 | Dundee | 33 | 10 | 11 | 12 | 44 | 54 | -10 | 41 |
| 7 | Hibernian | 33 | 9 | 12 | 12 | 44 | 51 | -7 | 39 |
| 8 | Motherwell | 33 | 8 | 13 | 12 | 46 | 51 | -5 | 37 |
| 9 | Aberdeen | 33 | 8 | 11 | 14 | 35 | 49 | -14 | 35 |
| 10 | St Johnstone | 33 | 7 | 10 | 16 | 24 | 46 | -22 | 31 |
| 11 | Ross County | 33 | 7 | 9 | 17 | 32 | 56 | -24 | 30 |
| R | Livingston | 33 | 3 | 9 | 21 | 22 | 59 | -37 | 18 |
| > Scottish Premiership Full Table | |||||||||
