The Senegal international claims that the accolade means a lot to him and has thanked the fans for voting for him.
The 24-year-old, who signed for the Reds in a £34million deal from Southampton this summer, managed to score one goal in two league appearances in the month of August.
He told Liverpoolfc.com: "It means a lot. I have been working every day – every day in training and in the games – to give my best for the team.
"We have a great team with many qualities. Now we have to work to make the fans happy. We're going to take it game by game and try to win as many as we can.
"I want to thank everybody for this, especially the fans who voted for me, and I am very happy to win it.
"But it deserves to go to the whole team because without them, I would be nothing, so I want to thank them. We will try to give our best for the fans and to win games for them."