Arguably the world's best player, Messi is a five-time winner of the Ballon d'Or and has won eight LaLiga crowns and four Champions League titles among other trophies.
Fabregas, a former team-mate of the Argentina international's at Barca, said the 29-year-old's ability to stay modest deserved plaudits.
"I admire Lionel Messi a lot, because after what he's done in football, after what he's achieved, what he is to every kid in the world, to nearly every grown up in the world who likes football, he kept it so humble," the Spain international said.
"The way he is, the way he treats everyone, the way he lives his life with his wife, with his kids, so normal.
"It's not easy. It's not easy these days when everyone talks so highly of you and you've won so much for so many years, that you are the best player in the world - sometimes you lose it a little bit and you are not in the real world. But he is very, very much.
"And I appreciate that because I consider him my friend and it's not easy and for me it's fantastic that someone like him can be the way he is."
Messi is on track to be the top goalscorer in LaLiga for a fourth time, having struck 25 times this season.
His side return to action on Sunday with a trip to Granada, as they look to keep the pressure on league leaders and rivals Real Madrid.