Michu and Chico have quickly established themselves as key players under Michael Laudrup following positive starts to the season, and Rangel expects Hernandez to make an impact as well.
"It can be very difficult sometimes for players to arrive in a foreign country and adapt quickly," he told the club's official website. "It's a totally different country and the style of football can take some time to get used to.
"But I think Michu, Chico and Pablo have settled in very quickly.
"Michu has already scored six goals this season, which is brilliant considering he's only played in eight games.
"Chico, like Michu, is already a big favourite with the supporters. He is learning to speak English to communicate more with the rest of the team, but I think he is settling in very well.
"Pablo, too, is quickly adapting into this team and the Premier League. Of course, he arrived later than Michu and Chico, but he is a quality player.
"He's a Spanish international, which says a lot about his quality, and I think he gives the manager even more options going forward.
"I think he will get better and better with every game he plays, and that's great news for us."