Johnny Manziel -- 'He's Not a Bad Teammate' ... Says Browns Player

Johnny Manziel hasn't lost the support of his teammates ... so says a Cleveland Browns player who tells TMZ Sports, "most guys on this team want him to be the one leading us next year."

The player -- who spoke to us on the condition of anonymity -- says everyone knows Johnny made mistakes ... but most teammates are chalking it up to immaturity.

"He's still learning, He's still a rookie. He needs more time to figure out life at the next level."

The player adds, "Johnny hasn't been a bad teammate" ... and several Browns believe JM's screw-ups have been blown out of proportion by the media because he's so famous.

"He has to live his life. As long as next year we compete for the playoffs, guys in this locker room will support him in his maturation process."