Riewoldt was seen to have been hindered by a hand injury in the opening half of the match, however played out the game to record six disposals, two marks a goal.
The veteran forward will undergo further assessment on Friday morning, with Riewoldt potentially requiring surgery and a stint on the sidelines.
"He'll have scans to confirm it that’s why he went off early and probably struggled to hold the ball a little bit tonight. We'll get more details out when we find out possibly tomorrow."
Prestia was subbed out of the match early into the affair, with young defender Hugo Ralphsmith coming into the game.
The former Sun has battled ongoing soft tissue setbacks across his 174-game career, having suffered a similar setback in the pre-season of 2021 before being limited to just the nine appearances in either of the past two seasons.
Hardwick said Prestia was a "significant loss" in the match, with Richmond's midfield tested against a fit and firing Blues engine room ensemble.
"It's just disappointing; he's had as good a pre-season as he's had. He is so important to the way we play. I feel like he's barely played for two and a half years," Hardwick added.
"To get 10 touches in the first quarter and lo and behold we're up and going and then he goes out. He is a significant loss. I just really feel for the kid. He is so important to the way we play and the culture of the place as well.
"He was really disappointed and I'm disappointed for him. We want to see him on the field and up and about. It’s a challenging stage for him."
The loss sees the Tigers fall to Carlton for the first time since the 2013 elimination final, ending an 11-game winning run for the Punt Road club.