Barcelona maintained their flawless start to the season after seeing out a hard fought 1-0 victory over Sporting Lisbon at the Estadio Jose Alvalade on Wednesday.
Valverde's men now comfortably sit at the top of group D, three points ahead of Sporting who are level with Italian champions Juventus on goal difference.
In a tight, cagey affair, Barcelona prevailed thanks to a Sebastian Coates own goal just after the half time break. Neither team showed any real attacking prowess throughout the game, although both teams remained very solid at the back, with Lisbon conceding just their second goal of the season at home.
Barcelona boss Ernesto Valverde, as reported by Goal.com, was pleased by his team's resilience and determination during the game, and admitted there is never an easy game in the Champions League.
"If you want to win big games you have to suffer," he said.
"We played with real determination and dominated the first half.
"When we went 1-0 up Sporting gritted their teeth and caused us a little insecurity. But, come on, this is the Champions League and it is never easy."
He also went onto address critics who have labelled this current Barcelona team as 'boring' compared to the squads we have seen in recent seasons.
As reported be ESPN, he said, "Everyone is free to say what they want.
"I don't get bored -- especially not when we win.
"There are times when you win in an exciting way, scoring lots of goals, and then there are other times when you have to suffer to win. That's how it is."
Barcelona now sit comfortably a top of group D, and host Greek champions Olympiakos who currently sit bottom having lost in both of their opening games.