The former Cameroon international had a major influence in the Argentine's development and gave him some important advice to help him blossom at the Blaugrana.
"[Messi] confessed to me that, thanks to my advice, which I am not going to reveal, his career had changed," Eto'o told DAZN.
"One day he said: 'Thanks to Samuel [Eto'o], my career changed'.
"He had to fix two or three things but he has always had the talent.
"I am proud and happy to see that he has written history which has yet to be finished, and it will be very difficult to beat what he has written."
Eto'o went on to recall Messi's first steps into the first team after being promoted from La Masia.
"He was going up and down from La Masia to the first team," he added.
"We already knew that one day Messi was going to be what he is.
"I am happy because he has made it in the end, thanks to himself.
"He showed me that nothing has changed.
"He is still the good person I met."