The Jaguars listed Blackmon as a limited participant in Wednesday's practice and will reevaluate him for swelling before deciding if he will be available for Thursday's session.
Alfie Crow from SB Nation's Jaguars blog, Big Cat Country, took a look at whether or not Jacksonville fans should be worried about the setback.
"While the news sent an initial panic through Jaguars land, it shouldn't. If Blackmon's ankle is still bothering him on Friday and he's limited in the final session of practice, then some worry might be appropriate.
It's likely that Blackmon will be listed as "limited" again on Thursday, but as mentioned the Friday session is what counts. Blackmon being on the field is important for the Jaguars offense, as he looks like a rookie receiver who can make an instant impact on the football field."
Blackmon caught 10 passes for 136 yards and one touchdown during the preseason, establishing himself as one of quarterback Blaine Gabbert's go-to targets in the passing game.
For more on the Jaguars, head over to Big Cat Country.
Justin Blackmon Interview - Jaguars Rookie WR (via sbnation)