News daily La Nacion said that a place in the defence and another in the attack are still up for grabs.
The paper predicted that the team will probably be:
Erick Lonis; Mauricio Wright, Luis Marin and Gilberto Martinez; Harold Wallace, Walter Centeno, Mauricio Solis and Carlos Castro; Wilmer Lopez, Ronald Gomez and Paulo Wanchope.
But Guimaraes has still to choose between Marin and Jervis Drummond, a player who might also replace Wallace on the right side of midfield.
Up front, Gomez has played well in the recent friendlies but Winston Parks could still be an option beside the "untouchable" Manchester City striker Wanchope.
Costa Rica will also face Turkey on 9 June and Brazil four days later, all in Group C.