The 31-year-old was released by the Baggies last month following a four-year spell at The Hawthorns.
He is now expected to sign a deal at Selhurst Park as Palace prepare for life in the Premier League, according to the Daily Mail.
Thomas, who started his career with Arsenal, arrived at West Brom from Portsmouth in 2009.
Restore Data
| Team | P | W | D | L | F | A | GD | PTS | |
| 1 | Sheffield UnitedSheff Utd | 33 | 22 | 6 | 5 | 47 | 23 | 24 | 70 |
| 2 | Leeds UnitedLeeds | 32 | 20 | 9 | 3 | 66 | 19 | 47 | 69 |
| 3 | Burnley | 33 | 17 | 14 | 2 | 39 | 9 | 30 | 65 |
| 4 | Sunderland | 32 | 17 | 11 | 4 | 49 | 28 | 21 | 62 |
| 5 | Blackburn RoversBlackburn | 33 | 15 | 6 | 12 | 39 | 31 | 8 | 51 |
| 6 | West Bromwich AlbionWest Brom | 33 | 11 | 15 | 7 | 42 | 31 | 11 | 48 |
| 7 | Coventry CityCoventry | 33 | 13 | 8 | 12 | 44 | 41 | 3 | 47 |
| 8 | Bristol City | 33 | 11 | 13 | 9 | 41 | 37 | 4 | 46 |
| 9 | Sheffield WednesdaySheff Weds | 33 | 12 | 9 | 12 | 46 | 50 | -4 | 45 |
| 10 | Watford | 33 | 13 | 6 | 14 | 43 | 48 | -5 | 45 |
| 11 | Middlesbrough | 32 | 12 | 8 | 12 | 50 | 43 | 7 | 44 |
| 12 | Norwich CityNorwich | 33 | 11 | 11 | 11 | 51 | 45 | 6 | 44 |
| 13 | Queens Park RangersQPR | 33 | 11 | 11 | 11 | 39 | 41 | -2 | 44 |
| 14 | Millwall | 32 | 10 | 11 | 11 | 32 | 33 | -1 | 41 |
| 15 | Preston North EndPreston | 32 | 9 | 14 | 9 | 34 | 38 | -4 | 41 |
| 16 | Oxford UnitedOxford Utd | 33 | 9 | 11 | 13 | 34 | 47 | -13 | 38 |
| 17 | Swansea CitySwansea | 33 | 10 | 7 | 16 | 34 | 46 | -12 | 37 |
| 18 | Portsmouth | 33 | 9 | 9 | 15 | 41 | 55 | -14 | 36 |
| 19 | Stoke CityStoke | 32 | 8 | 11 | 13 | 31 | 40 | -9 | 35 |
| 20 | Cardiff CityCardiff | 32 | 7 | 11 | 14 | 35 | 54 | -19 | 32 |
| 21 | Hull City | 32 | 7 | 9 | 16 | 32 | 43 | -11 | 30 |
| 22 | Derby CountyDerby | 33 | 7 | 8 | 18 | 33 | 46 | -13 | 29 |
| 23 | Plymouth ArgylePlymouth | 32 | 6 | 10 | 16 | 34 | 66 | -32 | 28 |
| 24 | Luton TownLuton | 32 | 7 | 6 | 19 | 30 | 52 | -22 | 27 |
| > Championship Full Table | |||||||||
