I worry about our attack when we have neither of the pace & direct threat in the front three of Mane or Salah.
Or
We have neither of the creativity of Lallana or Coutinho in CM.
Looks like the latter might be a possibility given Coutinho has this back issue and isn't training.
A CM of Henderson as the deepest CM, with Wijnaldum and Can would lack creativity. Wijnaldum has the talent to do it I feel & really should be looking to step up and be the leader in that regard without the other two. But last season he didn't really do that. He played very well, but mostly that was with his energy, simple use of the ball and defensive work. I'd love him to not play within himself as much if that is the midfield we go with and he is the one looking to feed the front three.
I'm not sure if it is possible anymore, given his injury history. But if Coutinho can't start I would like to see Henderson in the box to box role alongside Wijnaldum and Can as the deeper CM. So in effect Can & Henderson switching roles. I feel Henderson is better at pressing than Can and you do more pressing in that role. I feel Henderson is more creative. Let's not forget the season after we lost Suarez, Henderson was playing in that role and was our most productive player in the league that season with 6 goals & 9 assists. That was more productive than Sterling, Sturridge and Coutinho that season.
I wish they asked questions like that in the press conference, asking if Henderson can still do that role given his injury history and is he considered as one of the players who can do that role. Because if he is, when we don't have Lallana or Coutinho, I feel he could be our best option and Can always looks best as the deepest CM.
Instead we'll get predictable questions saying "are you looking forward to the new season Jurgen?", "Questions about Coutinho staying at the club" etc - all questions which we could probably answer for Klopp himself. Of course he's looking forward to the new season, he won't comment on transfer speculation... ask some questions where we might get some insight from our manager.
The other option I feel we could have if Coutinho doesn't play, is to go with a diamond formation. Salah and Firmino can play upfront. Salah has played upfront for Roma before to great effect. They'll offer a huge threat combined with their movement, the speed of Salah and Watford would be wary of playing too high of a defensive line. Then Mane could play behind then in the tip of a diamond. The concern about that though is is could narrow our play and expose our full backs more.
My preference assume Coutinho can't play would be to get Henderson back playing the role he used to play before Klopp took over. If we had Lallana or Coutinho fit, then I'd have him as the deepest CM. But they might not be fit and if the captain is capable of playing the box to box role, given his injury history, then I think he'd be a better option than Can in that role. As he is more productive, creative, the better presser and will allow Can to do what he's good at, being physical & dominant as our deepest CM to protect our defence.