With Arsenal having moved to within a point of the top four with a win over Stoke City on Saturday, the pressure was on Jürgen Klopp's men to deliver at the London the Stadium the following day.
But they acheived a crucial victory in style thanks to Philippe Coutinho's double and goals from Daniel Sturridge and Divock Origi.
Speaking after the game, Lallana revealed that there was a mood of confidence and not anxiety behind the scenes ahead of the game - a fact he believes is a great credit to his colleagues.
“It was a very calm atmosphere actually [in the dressing room],” he told Liverpoolfc.