In an ominous statement to their A-League rivals, Brisbane Roar coach Rado Vidosic believes latest arrival Do Dong-Hyun may make reigning Johnny Warren Medallist Thomas Broich more dangerous.South Korea under-20 international Do was unveiled by the Roar in Brisbane on Tuesday after the 19-year-old agreed to a three-season deal.Vidosic said the injection of left winger Do would ensure a more central midfield role for Broich, who claimed the A-League's best player award last season before helping the Roar clinch back-to-back championships.And that could spell big trouble for their opposition, Vidosic said.Asked if Do's signing made Broich more dangerous, the Brisbane mentor said: "You hope so - it definitely gets him more involved because in the middle you get more touches."With the speed that we have got now out wide we can really penetrate and be even more dangerous."Vidosic licked his lips at the prospect of Do - who trialled with the Roar in May - linking with the likes of fellow attacking weapons Broich, Ben Halloran and Besart Berisha."With the attacking brand and aggressive defence that we have used the last two years I am quite sure that we will again be one of the front runners," he said."If we can get all the small details right I am sure we will be very hard to defeat."Finally handed the reins after assisting previous head coaches Miron Bleiberg, Frank Farina and the championship-winning Ange Postecoglou, Vidosic was also confident he had already put his own stamp on the Roar."Now we are going to try to maintain all those qualities (that have won two titles) but also try to be sharp and try to penetrate as quickly as we can because now we have players who can do that quite effectively," he said."We are getting more and more combinations that we can apply. I am very excited about that."Do's signing takes the Roar's player list to 20.Brisbane are expected to fill their remaining visa spot by signing an overseas defender to replace Bahraini international Mohamed Adnan.