The South Korean midfielder moved to Loftus Road earlier this summer from Manchester United and Hughes believes that the signing was a signal of intent from ambitious chairman Tony Fernandes.
Hughes told the Evening Standard: "He is a statement of what we're trying to do. We're trying to be a club that has the ability to attract top players.
"A key player for many seasons for United, he was always involved in the crucial games, a player you could trust. He has the right attitude, right ability and can affect games at the highest level. He also gives us credibility."
QPR begin their new Premier League season by hosting Swansea City on Saturday.