The 30-year-old, who spent last season on loan at Bolton Wanderers, was signed by Steve McClaren for £4.5m from Stoke City just 18 months ago.
Tuncay made just five appearances during his time in Germany without scoring a goal.
The striker only found the net once for the Trotters, in a Carling Cup game against Macclesfield.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| C | Bayer LeverkusenB. Leverkusen | 34 | 28 | 6 | 0 | 89 | 24 | 65 | 90 |
| 2 | Stuttgart | 34 | 23 | 4 | 7 | 78 | 39 | 39 | 73 |
| 3 | Bayern MunichBayern | 34 | 23 | 3 | 8 | 94 | 45 | 49 | 72 |
| 4 | RB Leipzig | 34 | 19 | 8 | 7 | 77 | 39 | 38 | 65 |
| 5 | Borussia DortmundDortmund | 34 | 18 | 9 | 7 | 68 | 43 | 25 | 63 |
| 6 | Eintracht FrankfurtFrankfurt | 34 | 11 | 14 | 9 | 51 | 50 | 1 | 47 |
| 7 | Hoffenheim | 34 | 13 | 7 | 14 | 66 | 66 | 0 | 46 |
| 8 | Heidenheim | 34 | 10 | 12 | 12 | 50 | 55 | -5 | 42 |
| 9 | Werder Bremen | 34 | 11 | 9 | 14 | 48 | 54 | -6 | 42 |
| 10 | Freiburg | 34 | 11 | 9 | 14 | 45 | 58 | -13 | 42 |
| 11 | Augsburg | 34 | 10 | 9 | 15 | 50 | 60 | -10 | 39 |
| 12 | Wolfsburg | 34 | 10 | 7 | 17 | 41 | 56 | -15 | 37 |
| 13 | Mainz 05Mainz | 34 | 7 | 14 | 13 | 39 | 51 | -12 | 35 |
| 14 | Borussia MonchengladbachBorussia M'bach | 34 | 7 | 13 | 14 | 56 | 67 | -11 | 34 |
| 15 | Union BerlinUnion Berlin | 34 | 9 | 6 | 19 | 33 | 58 | -25 | 33 |
| 16 | VfL BochumVfL Bochum | 34 | 7 | 12 | 15 | 42 | 74 | -32 | 33 |
| R | FC Koln | 34 | 5 | 12 | 17 | 28 | 60 | -32 | 27 |
| R | SV Darmstadt 98Darmstadt | 34 | 3 | 8 | 23 | 30 | 86 | -56 | 17 |
| > Bundesliga Full Table | |||||||||
