The 34-year-old, who spent 11 years with the club before joining St Pauli in 2010, was released by Greuther Furth earlier in the summer.
"We had a vacancy in the attack of our reserve team and Gerald could help us out there," Schalke's director of sport Horst Heldt told reporters at a press conference.
A number of German clubs had been linked with the midfielder this summer.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | St Pauli | 34 | 20 | 9 | 5 | 62 | 36 | 26 | 69 |
| 2 | Holstein Kiel | 34 | 21 | 5 | 8 | 65 | 39 | 26 | 68 |
| 3 | Fortuna DusseldorfDusseldorf | 34 | 18 | 9 | 7 | 72 | 40 | 32 | 63 |
| 4 | Hamburger SV | 34 | 17 | 7 | 10 | 64 | 44 | 20 | 58 |
| 5 | Karlsruher SCKarlsruher | 34 | 15 | 10 | 9 | 68 | 48 | 20 | 55 |
| 6 | Hannover | 34 | 13 | 13 | 8 | 59 | 44 | 15 | 52 |
| 7 | SC PaderbornSC Paderborn | 34 | 15 | 7 | 12 | 54 | 54 | 0 | 52 |
| 8 | Greuther Furth | 34 | 14 | 8 | 12 | 50 | 49 | 1 | 50 |
| 9 | Hertha Berlin | 34 | 13 | 9 | 12 | 69 | 59 | 10 | 48 |
| 10 | Schalke 04Schalke | 34 | 12 | 7 | 15 | 53 | 60 | -7 | 43 |
| 11 | Elversberg | 34 | 12 | 7 | 15 | 49 | 63 | -14 | 43 |
| 12 | Nuremberg | 34 | 11 | 7 | 16 | 43 | 64 | -21 | 40 |
| 13 | KaiserslauternKaiserslautern | 34 | 11 | 6 | 17 | 59 | 64 | -5 | 39 |
| 14 | Magdeburg | 34 | 9 | 11 | 14 | 46 | 54 | -8 | 38 |
| 15 | Eintracht BraunschweigBraunschweig | 34 | 11 | 5 | 18 | 37 | 53 | -16 | 38 |
| 16 | Wehen WiesbadenWiesbaden | 34 | 8 | 8 | 18 | 36 | 50 | -14 | 32 |
| 17 | Hansa RostockHansa Rostock | 34 | 9 | 4 | 21 | 30 | 57 | -27 | 31 |
| 18 | VfL OsnabruckOsnabruck | 34 | 6 | 10 | 18 | 31 | 69 | -38 | 28 |
| > 2.Bundesliga Full Table | |||||||||
