The 32-year-old was on a season-long loan at Vicarage Road from Guangzhou Evergrande, but struggled to make an impact under Quique Flores.
The former West Ham midfielder made only three substitute appearances during his time with the Hornets.
Atalanta said that Diamanti would wear the No.23 shirt at the Stadio Atleti Azzurri d'Italia.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Leeds UnitedLeeds | 20 | 12 | 5 | 3 | 36 | 14 | 22 | 41 |
| 2 | Sheffield UnitedSheff Utd | 19 | 12 | 5 | 2 | 27 | 11 | 16 | 39 |
| 3 | Burnley | 20 | 10 | 8 | 2 | 24 | 7 | 17 | 38 |
| 4 | Sunderland | 20 | 10 | 7 | 3 | 29 | 15 | 14 | 37 |
| 5 | Blackburn RoversBlackburn | 19 | 10 | 4 | 5 | 23 | 17 | 6 | 34 |
| 6 | Middlesbrough | 20 | 9 | 4 | 7 | 34 | 25 | 9 | 31 |
| 7 | Watford | 18 | 9 | 3 | 6 | 26 | 24 | 2 | 30 |
| 8 | West Bromwich AlbionWest Brom | 19 | 6 | 11 | 2 | 21 | 14 | 7 | 29 |
| 9 | Swansea CitySwansea | 20 | 7 | 6 | 7 | 21 | 19 | 2 | 27 |
| 10 | Norwich CityNorwich | 20 | 6 | 8 | 6 | 35 | 30 | 5 | 26 |
| 11 | Bristol City | 20 | 6 | 8 | 6 | 25 | 25 | 0 | 26 |
| 12 | Sheffield WednesdaySheff Weds | 20 | 7 | 5 | 8 | 23 | 29 | -6 | 26 |
| 13 | Millwall | 18 | 6 | 7 | 5 | 20 | 16 | 4 | 25 |
| 14 | Luton TownLuton | 20 | 6 | 4 | 10 | 23 | 35 | -12 | 22 |
| 15 | Coventry CityCoventry | 19 | 5 | 6 | 8 | 25 | 27 | -2 | 21 |
| 16 | Derby CountyDerby | 20 | 5 | 6 | 9 | 22 | 26 | -4 | 21 |
| 17 | Stoke CityStoke | 20 | 5 | 6 | 9 | 21 | 26 | -5 | 21 |
| 18 | Preston North EndPreston | 19 | 3 | 10 | 6 | 18 | 26 | -8 | 19 |
| 19 | Oxford UnitedOxford Utd | 18 | 4 | 6 | 8 | 20 | 28 | -8 | 18 |
| 20 | Queens Park RangersQPR | 19 | 3 | 9 | 7 | 18 | 26 | -8 | 18 |
| 21 | Portsmouth | 18 | 3 | 8 | 7 | 21 | 30 | -9 | 17 |
| 22 | Cardiff CityCardiff | 18 | 4 | 5 | 9 | 17 | 28 | -11 | 17 |
| 23 | Plymouth ArgylePlymouth | 19 | 4 | 5 | 10 | 19 | 40 | -21 | 17 |
| 24 | Hull City | 19 | 3 | 6 | 10 | 17 | 27 | -10 | 15 |
| > Championship Full Table | |||||||||
