The Pirates’ Double-A affiliate Altoona announced on Thursday that it will hold “Roberto Clemente Night” next Friday, July 21st at Peoples Natural Gas Field and officially retire the Great One’s No. 21. The ceremony will take place at approximately 5:40 p.m., prior to a game against the Reading Fightin Phils. There will be a 21 plaque unveiled in right field, hung 21 feet above the ground, while representatives from the Clemente Museum in Pittsburgh will be there with a game-used bat, jerseys and other memorabilia.