4-4-2
It was a system which saw Barcelona romp to an irrepressible 14-point title win last campaign but there are notable tactical differences to a 4-4-2 set-up without Messi compared to with him.
Valverde's systems are typically balanced and reserved and this formation is a fine example of that. Coutinho, Alba, Malcom and Semedo can create overloads down the flanks while Busquets drops back to provide cover for Clement Lenglet and Gerard Piqué.
Suarez has evolved into somewhat of a hold-up forward at Barcelona and he can press a ball-playing centre-half before keeping the ball and unleashing it to Messi when the space opens up.
This is still an option with Dembélé, who has the pace to latch onto the flick-ons and through balls Suarez has become accustomed to playing to Messi.
The onus is typically on Barca players to feed the ball to Messi but in this system the attacking individuals have more freedom in the final third and Coutinho and Malcom also have the option of cutting inside and striking, with Suarez and Dembele splitting up-top.