Darren Sharper -- Hall of Famers Rally Against Him ... 'He Isn't Getting In'

Several NFL Hall of Famers tell TMZ Sports ... they are united AGAINST the possibility of Darren Sharper joining their elite group ... with one star putting it bluntly, "He isn't getting in."

As we previously reported, Sharper is still eligible to make the HOF -- despite the fact he's a convicted rapist -- because voters are instructed to IGNORE the players' off-the-field lives.

But multiple former NFL stars who are currently enshrined in Canton tell us they don't like the fact that Sharper could join them one day. Here are some of the strongest quotes:

John Randle (inducted 2010) -- "My gut says he'll never get in. At the end of the day, it looks bad upon the Hall if someone in prison for rape receives that honor. It taints the group."

Willie Roaf ( inducted 2012) -- "If Sharper was inducted, it would shine a bad light on the Hall. He would have to do a complete image makeover. I don't know if that's possible."

Dan Hampton (inducted 2002) -- "Darren Sharper has no business being considered for induction into this exclusive fraternity. The systematic commission of these heinous crimes that [he] has committed should preclude him from any HOF consideration. Simple as that."