This could open the door now for Lennie to go and get his man.
WBA paid £1.75m to sign Gregan and they want a return even though he only has one year left on his contract. There is an option of another year if the club decided to take it.
"Sean has stated he wants to leave us because he doesn't feel he will get adequate first team opportunities next season and wants regular football elsewhere," Chairman Jeremy Peace told the official WBA website.
"Therefore, the board has reluctantly accepted his written transfer request.
"Having paid £1.75 million to sign Sean only two years ago, we will only let him go if we receive an acceptable offer. Sean still has up to two years left on his contract and we are under no financial pressure to sell him or any of our players."