As of right now I would guess the forward lines to be
Vanek Hodson Pommers
Foligno Ennis Stafford
Ott Grigerenko Lieno
Gerbe Ellis/McCormick Tropp/Kaleta
Gerginsons might have a chance at the 4th line center after spending part of the season in Rochester as he adjusts to playing against grown men or be a call up in case of injuries. He could be the best option for a 4th line center that the team has right now.
They may want Grigerenko to go with another European type player so Lieno might be used on the RW. Ott would bring grit to the line and take faceoffs.
The problem with the team the way it is currently constructed is that there is no shut down line to turn to. There is no quality defensive center yet. Perhaps Girginsons can become that but he may not be there yet.
I think Ruff lost confidence in Luke Adam (or Luke Adam lost his confidance due to Ruff) so I wouldn't be surprised if he gets traded in some package deal along with a defenseman.
I think Lieno is the weak link of the forwards. He's not a leader, he's not tough or physical, his offense is poor (he's only had 1season over 10 goals 0 seasons over 20 goals, he doesn't play the penalty kill, he's not a great defensive forward, he lacks size, he lacks great speed. I just don't see how he fits.
We all know that Ruff juggles his lines all over the place so take this with a grain of salt.