The duo were set to go head-to-head in the UEFA Champions League next week for the first time since Ronaldo traded Real Madrid for Juve in 2018, but the reunion appears to have been scuppered after the Portugal star tested positive for COVID-19 again on Thursday.
UEFA protocol dictates that all players must test negative for the coronavirus a week before any European competition match, effectively ruling the five-time Ballon d'Or winner out of Wednesday's tie.
However, varying reports from England and Spain have since alleged that Juve will request permission to circumvent this provision by having Ronaldo take another test within 24-48 hours of the match.
Speaking ahead of this weekend's El Clasico, Messi revealed that clashes with the 35-year-old were always special occasions and that he hoped his long-time nemesis would be available for the upcoming clash.
"Obviously when Cristiano played for Real Madrid the games were special," Messi told DAZN. "Matches against them always are, but with Cristiano on the pitch they took on a particular significance.
"That is now in the past and we look forward to today's challenges. Wednesday there could be this challenge and we hope Cristiano can be there and will soon recover from COVID."