Mascherano left Liverpool and joined Spanish giants Barcelona in a £18million deal this summer.
He told The Sun: “While Manchester City, Chelsea and Manchester United were spending big money, Liverpool couldn’t because they had no money.
“The situation is clear to me. When you want to fight for big things, titles, you must have a big team to win.
“But, at Liverpool, that wasn’t the case.
“That was the main reason we didn’t qualify for the Champions League and all players want to test themselves at that level.”
He added: “It is not easy to leave a team when you have been there almost four years.
“The Liverpool people and fans treated me very well. I cannot say anything against them and they will always be in my heart.
“But, though it was difficult, I knew my time there was over. Finished. I needed to go.”
He added: “I try to watch all of Liverpool’s games on TV. They have had a tough start but I’m sure they’ll get much better.
“There have been a lot of problems with the owners and this has affected things on the pitch.
“Now this has been sorted out, I think things will get better for the team.”