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 | 31 | 18 | 9 | 4 | 57 | 33 | 24 | 63 |
| 2 | Holstein Kiel | 30 | 19 | 4 | 7 | 60 | 34 | 26 | 61 |
| 3 | Fortuna DusseldorfDusseldorf | 30 | 16 | 7 | 7 | 64 | 35 | 29 | 55 |
| 4 | Hamburger SV | 30 | 14 | 7 | 9 | 55 | 42 | 13 | 49 |
| 5 | Karlsruher SCKarlsruher | 30 | 12 | 10 | 8 | 61 | 45 | 16 | 46 |
| 6 | Hannover | 31 | 11 | 13 | 7 | 53 | 39 | 14 | 46 |
| 7 | Hertha Berlin | 31 | 12 | 9 | 10 | 63 | 52 | 11 | 45 |
| 8 | SC PaderbornSC Paderborn | 30 | 12 | 7 | 11 | 46 | 49 | -3 | 43 |
| 9 | Greuther Furth | 30 | 12 | 6 | 12 | 40 | 43 | -3 | 42 |
| 10 | Elversberg | 30 | 11 | 7 | 12 | 44 | 52 | -8 | 40 |
| 11 | Nuremberg | 30 | 10 | 7 | 13 | 38 | 56 | -18 | 37 |
| 12 | Magdeburg | 30 | 9 | 9 | 12 | 42 | 46 | -4 | 36 |
| 13 | Schalke 04Schalke | 30 | 10 | 6 | 14 | 46 | 56 | -10 | 36 |
| 14 | Eintracht BraunschweigBraunschweig | 30 | 10 | 4 | 16 | 33 | 41 | -8 | 34 |
| 15 | Wehen WiesbadenWiesbaden | 30 | 8 | 8 | 14 | 32 | 41 | -9 | 32 |
| 16 | Hansa RostockHansa Rostock | 31 | 9 | 4 | 18 | 27 | 51 | -24 | 31 |
| 17 | KaiserslauternKaiserslautern | 30 | 8 | 6 | 16 | 46 | 59 | -13 | 30 |
| 18 | VfL OsnabruckOsnabruck | 30 | 5 | 9 | 16 | 27 | 60 | -33 | 24 |
| > 2.Bundesliga Full Table | |||||||||
