The 23-year-old has been in impeccable form for club and country, playing a crucial role for Barcelona as they won an incredible treble this season, while he has already been made the Selecao captain under Dunga.
Jefferson, though, feels the attacker is not being respected properly in his homeland and feels he is the key player for the national team.
"Neymar has assumed a fundamental role in the team - he is the leader, our captain. He is well above average and makes all the difference for us and Barcelona," he told reporters.
"In Brazil he is still being criticised, which is something I don't understand. He has this bold, cheeky style which is his own. He is a player that is tough to beat. He will definitely become one of the greatest. It's a privilege to play alongside him.
"We are aware that some of us have to carry the burden, while the others are allowed to shine. We must humbly acknowledge that only a few players, especially our forwards, are able to decide a match."
After a narrow, Neymar-inspired 2-1 win over Peru in their Copa America opener, Jefferson has urged his side to be careful heading into their clash with Colombia, highlighting James Rodriguez and Radamel Falcao as the dangermen.
"I like to study my opponents a lot, as the match comes closer. I will watch their game against Venezuela with the coaching staff," Jefferson said in a press conference.
"I know the more expercienced players like James and Falcao, who we must be aware of. They are a strong team, with excellent marking, if we let them be comfortable we might get into trouble. They need the win so we must be very careful.
"The Copa America is being played at a high level, as we expected. This year's might be one of the toughest in history, you can see that in matches as a lot of teams are getting surprising results, so we must be sure to grab the win at every opportunity.
"Everybody wants to win at the Selecao and Dunga brings a lot of confidence to the players."