Hiddink said the 27-year-old regretted angering Redknapp by storming straight to the dressing room after being substituted against Manchester City last month.
"He realised he was wrong," said Hiddink. "The key for Roman now is to demonstrate his desire to play and to win - both in training and in matches.
"He should have a burning desire to show his quality. We need him to show it in Helsinki, regardless of how long he gets against Finland."