He's played about 3700 minutes (equivalent of 41 games) in 64 games over the last 2 years... That's clearly not enough time especially considering how disrupted its been due to injuries.The more he plays the better he will get IMO.
I think He has to play @ anfield as well. They wont be able to compress us and press with the same numbers they did in the first leg because of the speed demebele offers us compared to Coutinho.
442 with 4 players who play as classic CMs: Coutinho-Busquets-Rakitic-Vidal is a way stronger defense than ANY variation where one midfielder is hogging a touchline in defense and defends as a pure winger.
For example, today Arthur, Busquets, Rakitic, Vidal is the strongest possible defensive midfield line, or the one with Roberto, as long as he isn't hogging a touchline too much like against Roma.
So, with Dembele in 442 or 433, you are adding some fear to Liverpool since they can be exploited on counters.
But then, you are losing a lot of midfield's balance and defending if you play Dembele instead of one classical central midfielder.
On the other hand, if you play Dembele, you are getting a double risk:
1. our defense is way weaker
2. and if you create a deadly counter for him, you never know whether he will score Messi-esque goal out of nowhere of pull Alexis Sanchez/Dembele and slip three times in a row, miss the ball or pick the dumbest solution in a box every time.
IQ and logic would say: start 442 with Messi-Suarez, and behind them one out of 3 lineups:
Coutinho-Busi-Raki-Vidal
Busi-Raki-Arthur-Vidal
Busi-Raki-Vidal-Roberto
If a score will be good, Dembele can enter in the last 20-30 minutes.
If a score will be tight, Dembele can again enter in the last 20-30 minutes.
We will probably score at least 1 either way.
And Liverpool will need to attack like crazy and score 5.
Dembele will get a chance in the last 30 minutes, either way.