The way Barca lost yesterday, being completely dominated in all areas, while nothing worked from the keeper to the forward, says a lot about tatics, formation and the team in general. If someone watch games when teams are being completely dominated from the first minute till the end, it's most due to wrong, dumb tatics. So it's easy to realize that it's is really hard for just one player to impact the game.
Barca spent most of the time getting pressed and having to pass back until Ter Stegen kicks to Suarez. In the few moments Barca had time to play, we just played slow side-passes until someone lost the ball or ball to Ter Stegen then Suarez again. It was the same cycle the whole game.
Can you guys imagine 10 players playing like yesterday and only Messi running around and making things happen up and down, dribbling, passing, shooting and scoring? I can't. Neither Salah, Ronaldo, Neymar, could have done better yesterday if the whole team plays terrible like Barca did.
My point is that Messi should and could have done much better in the last seasons in CL, putting more effort and focus in every action, helping teammates, making himself available more often, trying new things when usual stuff isn't going well. But there wasn't much that he could have done if we look to yesterday game. It was Barca at their worst game and Roma at their best, nothing that only one guy could change.
To conclude I think Barca needs a big big rebuild in probably every area, except the goalkeeper. It's time to some old guys to say goodbye, time to release dead weight, time to sell most of the bench and bring new defenders, new midfielders, new strikers and specially a new coach. Could write a textbook about Valverde weird actions, but will just leave this: Your desire to win should be always bigger than your fear of lose and it seems that Valverde thinks the opposite.