Tupou is a healthy scratch for Sunday's game against the Colts, Katherine Terrell of ESPN.com reports.
The 24-year-old was recovering from a sprained MCL, but it appears he's shaken the injury. Still, the Bengals weren't ready to insert him into the lineup. Tupou's absence will leave Ryan Glasgow as the lone backup defensive tackle for Week 1.
Tupou, who was carted off the field Wednesday, was seen wearing a knee brace Thursday, Jim Owczarski of The Cincinnati Enquirer reports.
It was originally reported that Tupou suffered an ankle injury during Wednesday's practice, but it's now been discovered that it was his knee. Getting carted off the field is still definitely not a good sign for defensive lineman, and depending on the severity of the injury, Tupou's chances of making the Bengals' final roster could be even lower than they were entering training camp.
Tupou suffered a right ankle injury Wednesday, Paul Dehner Jr. of The Cincinnati Enquirer reports.
Tupou was reportedly carted off the practice field. The 2017 undrafted free agent played only one game with the Bengals last season and did not record a single tackle. Missing any amount of time due to injury would certainly impact Tupou's chances of securing a role with the team, as the 24-year-old faced an uphill battle to make the 53-man roster even when healthy.