Coutinho told reporters afterwards that his side's approach to the game served them well against a "difficult opponent".
"Dembele is a great player and against Malaga he proved it," the Brazilian said. "His cross was perfect.
"We came to play a difficult game and we scored early. With one more goal, we controlled the match and we left happy with the three points. Now we can think about Chelsea."
Barcelona are level with the Blues going into the Champions League second leg on Wednesday.