The horror incident occurred during the first half of the match, which finished 5-1 to the defending league champions, as the 27-year-old was reportedly caught by an accidental stamp from a Corinthians player during a challenge.
Blood quickly began to seep through, staining his white shorts, and he was forced into temporarily removing himself from the action in Sao Paulo to swap them for a fresh pair.
Henrique valiantly attempted to play on through the truly excruciating pain.
However, he was substituted by boss Domenec Torrent six minutes before the interval and received immediate medical treatment upon his arrival in the dressing room.
The bleeding did eventually stop but Henrique’s condition is still being closely watched by club staff.
He signed for Flamengo in January and has made nine appearances in Brazil’s Serie A this season.
The club will be hoping for a return to fitness in time for Sunday’s top-of-the-table clash against leaders Internacional, with Flamengo able to return to the summit with victory.
Testicular injuries are rare in football, but not unheard of.
Remarkably, the Liverpool-born centre back played through severe pain for 18 minutes to complete the match before undergoing surgery.
In the same month, Gillingham’s Chris Whelpdale suffered a torn scrotum during a 2-1 win at Crawley Town, with the player needing five stitches to seal the wound after the match.