If Osvaldo signs I would play:
Boruc
Clyne Maya Lovren Shaw
Schneiderlin Wanyama
Gaston Rodriguez
Lambert Osvaldo
Get our best players onto the pitch and take teams apart. I am concerned that we could squander gaston's talent and if Osvaldo comes in I can't see him playing centrally with Lambert always dropping deep. On the other hand gaston will have a good outlet in osvaldo so the move will surely be positive long term.
It's up to him to play himself into form but I don't think him playing out wide, tracking fullbacks and pressing for much of the game is the best thing for Gaston although it's what the system requires. If Osvaldo comes in I think Gaston is going to have to play better than either Osvaldo or Lambert to ensure he plays centrally with some luxury. As he is at his best when he recieves the ball centrally and has options running in behind. An in form gaston, as the liverpool game showed is still handy out wide but it isn't where he can have the most influence.