Swansea City midfielder Joe Allen reportedly has a clause in his contract which allows the Welshman to join any of the Premier League 'big five' for £15m.
The 22-year-old, who is currently on Team GB Olympic duty, has been strongly linked with a move to Liverpool this summer.
It is understood that the Reds have so far failed to raise their opening offer of £10m, but according to The Mirror, an additional £5m would trigger a clause in Allen's contract.
Manchester United, Manchester City, Chelsea and Arsenal are also among the reported 'big five'.
