Song signed from Barcelona in the summer, but the former Arsenal man believes their in-form striker would get more credit if he was playing in the Champions League.
Sakho has scored six goals so far this term for the Hammers, playing pivotal roles in wins over the likes of Liverpool and Manchester City, which has helped them into the Champions League places at this early stage of the season.
In an interview with the Daily Mirror, song said: "When you look at the way he has started, it's amazing. He doesn't get the credit he deserves but he was proved his quality in every game.
"He is a young player, he is in a new country and he is playing a new style of football so to do what he has done is fantastic.
"This guy - he scores goals, he tackles. He is just trying to find his way. But he has the chance to be one of the best players in the future."
Sakho, along with fellow new signing Enner Valencia, have been one of the main reasons why the Hammers have got off to such a good start.
So far Sakho has scored a total of seven goals from eight appearance in all competitions, and is one of the best performing players in the Premier League so far.
The way they get after their opponents is relentless as they rarely get time to rest against the pacey duo.
Song himself has been impressive at the heart of the Hammers midfield by adding presence, steel, experience and vision that has seen him play at the very highest level.