And, on the right, they have Dembele. Sergio Asenjo pushed the shot into the path of Coutinho to tap in. The Villarreal goalie denied the attempt, but couldn't secure a catch.
This summer, then, would appear the perfect time to introduce the Brazilian to the rigours of La Liga.
Barca got goal No. 2 after some magic from Andres Iniesta.
Arthur Melo is currently his own protracted farewell at Gremio, and if he can sustain Sunday's startling performance to down Santos the future - and present - should be bright for the Blaugrana.
Yet Spanish outlet Don Balon say Messi wants Dembele to stay at the club.
Referee Alejandro Hernandez Hernandez wrote in his report on the game that the player had been sent off for "striking an opponent with his arm with excessive force while the ball was not near enough to be in dispute". He was then injured again as Barca's main men continued to lead the title charge. Iniesta immediately passed back to the superstar.
Villarreal got on the board with a 53rd-minute goal by Nicola Sansone. He converted from the spot in the final minute of stoppage time, not long after Borja Mayoral scored Madrid's first goal in the 87th. Barcelona's decision melted many hearts on social media as fans hailed the move to recognise the contribution of mothers the world over.
Dembele arrived at Barca during the off-season with massive expectation due to his exorbitant transfer fee, as the direct replacement for Neymar.
"We're very pleased with the match".
After Phillipe Coutinho opened the scoring after just 8 minutes, Iniesta teed up Jordi Alba who passed for Paulinho to make it 2-0 and his wonderful ball over the Villarreal defense allowed Leo Messi to net his 35th league goal of the season. Further negotiations will be required to bring forward a deal that had been expected to be finalised in 2019, but which has been made more urgent by Iniesta's exit.
Dembele scored another goal six minutes later, taking a breakaway and beating three defenders, before chipping Asenjo.