Injuries: Ryan Kelly on crutches after Colts practice

The Indianapolis Colts head into the preseason as a banged-up operation.

While quarterback Andrew Luck and his on-the-mend shoulder loom as a raging question mark for Week 1, plenty of teammates are dealing with injuries of their own.

Phillip Dorsett missed his fourth consecutive practice on Thursday with a hamstring injury, putting a critical camp on hold for the third-year receiver, per multiple reports.

Meanwhile, reliable second-year centerRyan Kelly left the practice field with an unknown injury. Longtime Colts beat writer Mike Chappell reported the pivot was later "spotted on crutches." Kelly is expected to miss a few weeks, according to a report from WTTV-TV.

Also for the Colts, heavily touted rookie running back Marlon Mack missed another session due to a shoulder injury, while linebacker Jon Bostic is out until next week after having a plate inserted into his fractured finger, per Stephen Holder of The Indianapolis Star.

Few teams in August have been heavier swarmed by the injury bug. Don't expect to see any of these players suit up when the Colts host the Lions on Sunday night.

Other injuries we're tracking on this Thursday -- a day stuffed with no less than seven preseason affairs up ahead:

1. Updating our story from Wednesday night, Panthers second-year defensive tackle Vernon Butler is believed to have suffered a knee sprain in Wednesday's 27-17 win over the Texans, per NFL Network Insider Ian Rapoport.

2. Seahawks receiver Doug Baldwin left late in practice Thursday with an undisclosed injury to what was apparently his leg, according to the Seattle Times.

3. Slow start for Titans running back DeMarco Murray, who sat out his eighth straight practice with a hamstring injury, per the Tennessean.

4. Redskins outside linebacker Junior Galette is dealing with a hamstring injury, but the team isn't concerned that it will be an issue, per ESPN.

Jay Gruden said linebacker Trent Murphy (knee sprain) and safety Su'a Cravens (knee) will both have MRIs.

5. Jets coach Todd Bowles told reporters that running back Bilal Powell (sore neck) will not play in the Jets preseason opener against the Titans, while backfield counterpart Matt Forte's (hamstring) status is still yet to be determined.

6. Cowboys wideout Brice Butler has a sprained foot, and the team will take another look at it, per the Dallas Morning News.

Tyrone Crawford will spend next few days in a walking boot to support his right ankle post lateral sprain, NFL Netowrk's Jane Slater reports per a source informed of the situation.

Linebacker Sean Lee left practice early with a hamstring injury, per Cowboys coach Jason Garrett. Slater reports, however, that the team doesn't believe the injury is severe.

7. Lions tackle Rick Wagner left Detroit's joint practice with Indianapolis Thursday with an undisclosed injury, according to the Detroit Free Press.

8. Vikings cornerback Trae Waynes did not return to return to the game vs. the Bills after suffering a shoulder injury.

9. Dolphins linebacker Raekwon McMillan did not return after suffering a knee injury.

10. Packers corner Damarious Randall was diagnosed with a concussion, per the team.

Wide receiver Malachi Dupre was carted off the field and transported to a local hospital after suffering an apparent injury. Early reports on Dupres' status, however, were positive.

11. Browns safety Ibraheim Campbell (concussion) did not return to their game against the Saints.

12. Broncos defensive end Billy Winn was carted off and ruled out with a knee injury, the team announced.

Safety Orion Stewart made an early exit after suffering a neck injury.

13. Bears running back Ka'Deem Carey suffered a quad injury and didn't return.

14. Bills coach Sean McDermott said running back Jonathan Williams suffered a hamstring injury in Buffalo's loss to the Vikings.