"We have a lot of players with experience in the Champions League and that was good for us," he told liverpoolfc.tv. "Even with our younger players, you can look them in the eye and know they have confidence and that they know what to expect. We are all together.
Mascherano admits the departure of Arsenal midfielder Mathieu Flamini through injury shortly before half-time was a turning point in the game.
"When Flamini got injured, maybe the game changed a bit because he was playing really well," he said. "But we knew Arsenal are a good team and very dangerous.
"You could see from their second goal how dangerous they are on the counter-attack. But luckily for us we managed to go down the other end and get a goal with our next attack.
"We are very happy getting to the semi-final, and we need to enjoy this moment. We know reaching the last four in the Champions League is a difficult thing to do, so we are happy. We've had two very difficult matches against Arsenal.
"In the first 20 minutes we didn't play well, we played badly, but the game changed on Sami Hyypia's goal, it was good for us.
"I don't know if it was our best match for us in this season's Champions League, but we did well after the first half hour."