Rangel also claims that the Chilean will be a red-card candidate come Sunday.
The Swansea defender's comments come just days before the clubs meet for the first time in the Barclays Premier League in a game which has been eagerly-anticipated by both sets of fans after a two-season absence.
Previous encounters have proved to be fiery affairs and Sunday's contest at Cardiff City Stadium is likely to be no different.
And right-back Rangel has raised the temperature with his comments on Medel.
The midfielder joined the Bluebirds in an £11million deal from Sevilla during the summer, and has made a fine start to life in English football, producing several impressive displays.
The 26-year-old's disciplinary record has come in for scrutiny after he saw red seven times in 90 outings for Sevilla, one of which came after a clash with Swansea's former Real Betis midfielder Jose Canas.
Rangel believes his approach could make Medel a target, and also stated Cardiff paid too much to secure the defensive midfielder, despite his positive start to life in a red shirt.
"He's a hard working player. He's a holding player and aggressive, we know that," said Rangel.
"He likes contact with other players.
"He's had an experience with Canas before, who got him sent off.
"That shows you that in these kind of games there are a lot of craziness and intensity.
"If you are clever enough you can get him sent off, but he's only one player."
He added: "I think Cardiff paid too much money for him because he's a holding midfielder not a goalscorer.
"But they've been doing great, we have as well so hopefully it's going to be a healthy derby."
Rangel will also come up against former Swansea team-mate Steven Caulker, with the England centre-half having made the switch to Cardiff from Tottenham.
Caulker enjoyed an excellent loan spell at the Liberty Stadium during the Swans' maiden Premier League campaign, but will be hoping to bring about their downfall this weekend.
But Rangel retains an admiration for Caulker's ability, and admits he feels Cardiff have made a good start to life in the top flight.
He said: "For us he (Caulker) did great. Even at a young age he showed he had great potential at the back.
"I thought he was going to sign for a better team, but he signed for them so fair play.
"I think he's done well at Cardiff, along with Gary Medel as well - the two record signings.
"They are good at the back and up front we know they also have quality players like Peter Whittingham and Craig Bellamy.
"The won a game they didn't expect to win against Manchester City and they drew last Saturday away from home.
"They have done okay. For a team that has just come up it's always difficult to adjust.
"They haven't had easy games, but they picked up a good point against Everton as well.
"There's still a long way to go but they are looking good."