"Messi will play, because he always wants to play and I love that," he told a news conference on Monday.
"We had been thinking of giving him a rest but to have a player of the class of Leo, the best in the world by a long way without doubt, it would have been a sin not to give him to the team, to the people, not give ourselves (the pleasure).
"When I told him, he was super happy," added Maradona at the Loftus Versfeld stadium near Argentina's tournament base on the eve of the match at Polokwane.
Juan Sebastian Veron, who Maradona confirmed was returning from the calf muscle injury he suffered against Nigeria, would normally captain the side in Javier Mascherano's absence.
Asked if he had ever thought of making Messi his captain, Maradona said enigmatically: "You'll know tomorrow."
If Messi can score his first goal at this World Cup against the nation that conceded the last of Maradona's 34 international strikes so much the better, added the coach, who began the news conference by showing off a flashy, diamond-studded pair of sunglasses given to him on Father's Day on Sunday.
"I would love it for Leo to take the baton of the goal in that match," Maradona said referring to Argentina's 4-0 win over Greece at the 1994 finals, the teams' only previous meeting, in which Maradona scored and Gabriel Batistuta got a hat-trick.
"Above all because of the move which started in midfield... I hope Leo can score a similar goal, or better, or one that trickles agonisingly over the line but is a goal."
