| From | Team | Fee | Apps | Goals | To | |
|---|---|---|---|---|---|---|
| 2004 | Bristol Rovers | - | 2 | 0 | 2005 | (Player) |
| 2005 | Chelsea | - | 5 | 0 | 2010 | (Player) |
| 2007 | Plymouth Argyle | Loan | 15 | 2 | 2007 | (On loan) |
| 2007 | Queens Park Rangers | Loan | 9 | 1 | 2007 | (On loan) |
| 2007 | Chelsea | - | 5 | 0 | 2010 | (Player) |
| 2008 | Crystal Palace | Loan | 6 | 2 | 2008 | (On loan) |
| 2008 | Charlton Athletic | Loan | 3 | 0 | 2008 | (On loan) |
| 2009 | Birmingham City | Loan | 14 | 0 | 2009 | (On loan) |
| 2009 | Wigan Athletic | Loan | 18 | 1 | 2010 | (On loan) |
| 2010 | Swansea City | Β£500,000 | 82 | 28 | 2012 | (Player) |
| 2012 | Manchester City | Β£6,200,000 | 13 | 0 | 2015 | (Player) |
| 2013 | West Bromwich Albion | Loan | 8 | 0 | 2014 | (On loan) |
| 2015 | Aston Villa | Loan | 27 | 2 | 2016 | (On loan) |
| 2015 | Aston Villa | Loan | 9 | 1 | 2015 | (On loan) |
| 2016 | Celtic | Β£3,500,000 | 105 | 40 | 2020 | (Player) |
| 2020 | Preston North End | - | 78 | 12 | 2022 | (Player) |
| 2022 | Bristol Rovers | - | 98 | 12 | 2025 | (Player) |