Cameroon held Tunisia to a goalless draw in Rades in the first World Cup qualification play-off match on October 13 to set up a winner-takes-all clash in Yaounde.
"I'm here as a coach and it's qualification to the World Cup that we're interested in," Krol said at a press conference.
"It is a pity to have missed so many opportunities (in Rades). We were in control for most of the game, with some shaky phases from time to time.
"We must not forget who were in front of us. Now we will do everything to score a goal in Yaounde. We have what it takes to achieve it."
Cameroon coach Volker Finke could ring the changes to his side for the second leg, with QPR left-back Benoit Assou-Ekotto back in the squad along with Landry Nguemeo, Henri Bedimo, Gaetan Bong and Loe Raoul.
Sevilla midfielder Stephane Mbia is also in the squad but he sat out training on Friday following a knock.
Tunisian Prime Minister Ali Laarayadh, meanwhile, stepped in to help Krol as on Thursday he signed documents to naturalise two Tunisia players - Genk midfielder Fabien Camus and St Gallen midfielder Stephane Nater - ahead of the game.