I'm assuming their hope is that they hold on and Barca sign someone else, thus ending their interest, and Coutinho is then happy to stay.
Realistically though, I think his head has been turned, and while he might stay for another season, unless they're particularly successful, he's going. Might not be to Barca, but somewhere.
I certainly wouldn't have picked CAM as a position you needed to strengthen. I'd have gone ST, CB, LB, CM, GK in that order. If Coutinho goes priorities may be a bit different.