The Belgian forward, 25, joins the Championship side from Genk in his homeland.
In the last four seasons for Genk he has found the net on 69 occasions in the Belgian Pro League. At senior level for Belgium, he has two goals in 12 appearances.
Vossen is Boro's second signing of deadline day after they added Dutch winger Yanic Wildschut.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | West Bromwich AlbionWest Brom | 5 | 4 | 1 | 0 | 9 | 2 | 7 | 13 |
| 2 | Sunderland | 5 | 4 | 0 | 1 | 12 | 4 | 8 | 12 |
| 3 | Blackburn RoversBlackburn | 5 | 3 | 2 | 0 | 12 | 6 | 6 | 11 |
| 4 | Burnley | 5 | 3 | 1 | 1 | 11 | 3 | 8 | 10 |
| 5 | Watford | 5 | 3 | 1 | 1 | 9 | 5 | 4 | 10 |
| 6 | Sheffield UnitedSheff Utd | 5 | 3 | 2 | 0 | 8 | 3 | 5 | 9 |
| 7 | Oxford UnitedOxford Utd | 5 | 3 | 0 | 2 | 9 | 6 | 3 | 9 |
| 8 | Derby CountyDerby | 5 | 3 | 0 | 2 | 8 | 6 | 2 | 9 |
| 9 | Leeds UnitedLeeds | 5 | 2 | 2 | 1 | 7 | 4 | 3 | 8 |
| 10 | Middlesbrough | 5 | 2 | 2 | 1 | 6 | 4 | 2 | 8 |
| 11 | Swansea CitySwansea | 5 | 2 | 1 | 2 | 5 | 3 | 2 | 7 |
| 12 | Queens Park RangersQPR | 5 | 1 | 3 | 1 | 7 | 8 | -1 | 6 |
| 13 | Stoke CityStoke | 5 | 2 | 0 | 3 | 3 | 6 | -3 | 6 |
| 14 | Coventry CityCoventry | 5 | 1 | 2 | 2 | 5 | 6 | -1 | 5 |
| 15 | Norwich CityNorwich | 5 | 1 | 2 | 2 | 4 | 6 | -2 | 5 |
| 16 | Plymouth ArgylePlymouth | 5 | 1 | 2 | 2 | 5 | 9 | -4 | 5 |
| 17 | Bristol City | 5 | 1 | 2 | 2 | 6 | 11 | -5 | 5 |
| 18 | Millwall | 5 | 1 | 1 | 3 | 8 | 8 | 0 | 4 |
| 19 | Luton TownLuton | 5 | 1 | 1 | 3 | 3 | 7 | -4 | 4 |
| 20 | Sheffield WednesdaySheff Weds | 5 | 1 | 1 | 3 | 5 | 10 | -5 | 4 |
| 21 | Preston North EndPreston | 5 | 1 | 1 | 3 | 3 | 9 | -6 | 4 |
| 22 | Hull City | 5 | 0 | 3 | 2 | 2 | 6 | -4 | 3 |
| 23 | Portsmouth | 5 | 0 | 3 | 2 | 6 | 11 | -5 | 3 |
| 24 | Cardiff CityCardiff | 5 | 0 | 1 | 4 | 1 | 11 | -10 | 1 |
| > Championship Full Table | |||||||||
