Costa Rica played lots of attractive football in the qualifying stages but Guimares says this could change when they play their Group C matches against Brazil, China and Turkey.
"We won't be playing to entertain, we'll be playing to win," the 42-year-old told La Nacion newspaper.
The squad was the first of the finalists to arrive in the Far East and immediately launched into their first training session in Suzuka on Tuesday.
Manchester City's Paulo Wanchope has recovered from injury and took part in the practice but is unlikely to play in the friendly against J-League team Honda on Saturday.
Costa Rica's other injury worries Jervis Drummond, Hernan Medford and Reynaldo Parks are also making good progress.
The squad will complete a 10-day training camp before flying on to South Korea.