Coach Gus Bradley said Friday that he held Blackmon (hamstring, groin injuries) out of practice for the second time this week as a precautionary measure. Blackmon also didn't practice Wednesday; he was limited on Thursday.
"We feel better about Justin Blackmon," Bradley said. "He got quite a few reps yesterday and we wanted to make sure that he would be available on Sunday."
Blackmon caught 19 passes for 326 yards in the two games he has played since his return from a four-game suspension for violating the NFL's substance-abuse program. Those numbers are the best for any receiver in that span.
Shorts suffered an injury to the SC joint near his right shoulder in last week's loss to Denver and practiced on a limited basis Thursday and Friday. Bradley said the team wanted to see how Shorts responded to the work because it would have to sign receiver Jeremy Ebert from the practice squad if Shorts couldn't play.
Shorts, who leads the Jaguars (0-6) with 31 receptions for 411 yards, said he was confident he would be on the field.
"I'm getting better each day and we'll go from there," he said. "It's something I'll fight through."
Tight end Marcedes Lewis is scheduled to return to the field as well. He has played just two snaps this season because of a calf injury.
Bradley said Lewis' reps will be carefully monitored.
"I think we've got to be smart with him," Bradley said. "He feels really good, though. Of all the guys I've talked about he's probably the guy we're most confident about and the progress he's made this week."
In other injury news, receiver Ace Sanders (concussion), defensive end Jeremy Mincey (concussion), receiver Stephen Burton (concussion) and quarterback Blaine Gabbert (hamstring) have been declared out for the Chargers game.