Actually, Ray Mercer had 2 opportunity to face Rid*ick bowe. 1- In the summer of 1991, Mercer was scheduled to defend his title against Tommy Morrison, but the challenger was cut in sparring and Riddick Bowe stepped in. That bout didn’t take place either because Mercer injured his ankle and the Morrison bout was eventually rescheduled for October. https://www.ringtv.com/565353-best-i-faced-ray-mercer/ 2- On the undercard of Dokes_Bowe fight ,Mercer, who was scheduled to be Riddick's next opponent, met journeyman fighter Jesse Ferguson in what was supposed to be a tune-up before his championship match with Bowe. Instead, Ferguson controlled almost the entire fight and earned the upset victory by unanimous decision, knocking Mercer out of contention. So Big Daddy fought Ferguson instead. https://www.chicagotribune.com/news/ct-xpm-1993-03-25-9303250255-story.html. If Bowe fights a disciplined fight, sticks to his plan and keeps it mostly at distance, he would win the fight by UD. If he falls into his bad habits, the window gets bigger for Mercer.
Mercer was so inconsistent, he could go from fighting on even terms with Manny-trained Lennox to losing to Jesse Ferguson and getting shutout for 8 rounds by Francesco Damiani. If he has a bad night, then he loses a one sided decision to Bowe. Otherwise, he loses a competitive decision in a tough fight. Bowe’s defense was leakier from the outside, and Mercer would find a home for that jab along with some right hands. But he would eat a lot of those in return, along with a lot of uppercuts at closer range.