Barton, a veteran of the club's last fall from grace and subsequent immediate return to the top flight, fears for the Magpies as they attempt to drag themselves out of trouble with just 10 games of the season remaining.
Spaniard Benitez will send them out for the first time since signing a three-year deal - which includes an escape clause - at leaders Leicester on Monday evening, but one of the club's Class of 2009 has issued a stark warning over the price of failure.
Barton, who along with the likes of Steve Harper, Nicky Butt, Alan Smith and Kevin Nolan, formed the backbone of the side which secured promotion back to the Premier League at the first attempt at the end of the 2009-10 season, told BBC Radio 5 Live's Sportsweek show: "Hopefully Rafa can get that out of them because it would be an absolute travesty if a club of Newcastle's size and tradition were to drop into the Championship again.
Barclays Prem
17 S'land 25
18 Norwich 25
19 Newcastle 24
20 A Villa 16
"We did have a core group of men when we went down last time and I look into the dressing room now and there are a lot of foreign players, a lot of young foreign players and I just don't see the same core that will be in place to help them bounce straight back out of the Championship like we did, because it's a very, very tough league.
"It's difficult, it is very, very difficult because of the transition between the two leagues. You get a real culture shock.
"Obviously you go from playing 38 games to 46 and Saturday, Tuesday, Saturday and it's a really demanding league and there are some really tough places to go.
"You just wonder how young foreign players handle that because it will be an absolute culture shock for them."
Newcastle remain in 19th place in the table and a point from safety, and although Benitez is confident there is enough quality in the squad he inherited from Steve McClaren to escape, Barton insists that can only happen some of the players raise their game significantly.
He said: "I'm not wanting to dig anyone out because I was obviously in a QPR side that was relegated last year and I have been at Newcastle when Newcastle have been relegated, so I know how difficult it can be down at the bottom, and I am not accusing anybody of not putting it in or being unprofessional.
"But a lot of players have got to have a deep, hard, long look in the mirror and ask what more they can do for their football club because at this moment in time, there are a few of them who aren't at 100 per cent and don't seem to be giving everything for the cause."
Asked if Benitez will keep Newcastle up, current Burnley midfielder Barton was non-committal, but hinted that he was not overly optimistic.
He said: "No comment. My heart says one thing and my head says another thing.
"The club is a mess. It's a huge coup for them to be able to attract somebody of Rafa Benitez's calibre. What he has been promised by [managing director] Lee Charnley and [owner] Mike Ashley there, I don't know, but the club is in a huge mess and it's so sad because with common sense and being well-managed, this could all have been avoided.
"A club of Newcastle's size deserves a lot better than the current regime."