The signing comes after Andy O'Brien departed to Leeds on 1 January and could also be seen as a contingency plan if Trotters central defender Gary Cahill, who has been linked with several Premier League clubs, leaves.
Prince Abdullah hopes the new plan will have a similar effect on Saudi soccer as the creation of the Premier League in 1992 had on the English game, leading to better broadcast rights, growing fan bases, top-class players and investment in stadiums and other facilities.
Premier League chief executive Richard Scudamore had previously expressed his belief that Fifa could not stop the plan if the clubs receive the go-ahead from England's Football Association.