The 29-year-old, who had been without a club, has inked a three-year deal with the Serie A outfit.
He had only joined Parma last summer, but he left the club due to their financial problems and subsequent relegation from the top flight.
Costa has previously represented Italy at youth level.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| C | Inter Milan | 37 | 29 | 6 | 2 | 87 | 20 | 67 | 93 |
| 2 | AC Milan | 37 | 22 | 8 | 7 | 73 | 46 | 27 | 74 |
| 3 | Bologna | 37 | 18 | 14 | 5 | 54 | 30 | 24 | 68 |
| 4 | Juventus | 37 | 18 | 14 | 5 | 52 | 31 | 21 | 68 |
| 5 | Atalanta BCAtalanta | 36 | 20 | 6 | 10 | 67 | 39 | 28 | 66 |
| 6 | Roma | 37 | 18 | 9 | 10 | 64 | 44 | 20 | 63 |
| 7 | Lazio | 37 | 18 | 6 | 13 | 48 | 38 | 10 | 60 |
| 8 | Fiorentina | 37 | 16 | 9 | 12 | 58 | 44 | 14 | 57 |
| 9 | Torino | 37 | 13 | 14 | 10 | 36 | 33 | 3 | 53 |
| 10 | Napoli | 37 | 13 | 13 | 11 | 55 | 48 | 7 | 52 |
| 11 | Genoa | 37 | 11 | 13 | 13 | 43 | 45 | -2 | 46 |
| 12 | Monza | 37 | 11 | 12 | 14 | 39 | 49 | -10 | 45 |
| 13 | Hellas VeronaHellas Verona | 37 | 9 | 10 | 18 | 36 | 49 | -13 | 37 |
| 14 | Lecce | 37 | 8 | 13 | 16 | 32 | 54 | -22 | 37 |
| 15 | CagliariCagliari | 38 | 8 | 12 | 18 | 42 | 68 | -26 | 36 |
| 16 | FrosinoneFrosinone | 37 | 8 | 11 | 18 | 44 | 68 | -24 | 35 |
| 17 | Udinese | 37 | 5 | 19 | 13 | 36 | 53 | -17 | 34 |
| 18 | Empoli | 37 | 8 | 9 | 20 | 27 | 53 | -26 | 33 |
| R | SassuoloSassuolo | 37 | 7 | 8 | 22 | 42 | 74 | -32 | 29 |
| R | Salernitana | 37 | 2 | 10 | 25 | 29 | 78 | -49 | 16 |
| > Serie A Full Table | |||||||||
