At a press conference at Old Trafford today, Reds chief executive David Gill confirmed the game against the FA Cup winners will be added to United's existing commitments in South Africa.
"We're looking forward to a carnival atmosphere when we play in Nigeria."
Of course, the Reds are also due to face Portsmouth at Wembley in the Community Shield on Sunday 10 August.
"We didn't plan it to be a dress rehearsal for the Community Shield," Gill laughed, "but it's a nice coincidence.
"Those players who are involved in and do well at the European Championships won't make the trip [to South Africa or Nigeria]."