INDIANAPOLIS – Another day did nothing to clear the air regarding the availability of Anthony Richardson and Ryan Kelly for the Indianapolis Colts’ Sunday test against the Ravens in Baltimore.

Both players are in the NFL’s concussion protocol, and both did not practice for a second straight day. As was the case Wednesday, Richardson watched Thursday’s practice.

There’s still time for Richardson and Kelly to maneuver through the league’s protocol, but that time is slipping away. Along with participating in non-contact, then a contact practice setting, they must be cleared by the team’s medical staff and an independent neurologist.

The last time a Colts quarterback missed a start because of a concussion was Andrew Luck in 2016. He sustained the brain trauma in week 11 against Tennessee and was unable to go through concussion protocol in time for the quick-turnaround Thursday night game with Pittsburgh. 

On Wednesday, Shane Steichen was asked if it would be possible for Richardson to start even if he missed a majority of practice while dealing with the concussion.

“I think it depends,’’ he said. “You just have to talk through things with him still even though he’s not getting the reps. We’ll see.’’

Steichen repeatedly insisted he and the coaching staff would defer to the medical staff when determining the status of Richardson and Kelly.

If Richardson is out, veteran Gardner Minshew II will make his 25th career starter, but just the fifth in the past three seasons.

If Kelly is out, Wesley French is in line for his first career start.

French replaced Kelly for the second half of last Sunday’s 31-20 win at Houston and benefited from getting game reps with Minshew. Practice reps this week should prove invaluable.

“Being close to the guy and the more work you get with the guy, obviously the better connection with him you have on and off the field,’’ said French. “So, timing-wise, rhythm-wise the longer you’re with somebody, the better it becomes. Every single rep you’re just on the same page every single play.

Just getting reps with Gardner definitely helps. Whatever happens, we’re just going to get it done. I’m really excited to get out there with him and have some fun. Every time you get a chance to play ball, it’s a great time.’’

French, who joined the Colts as an undrafted rookie last season, is the Colts’ No. 3 center. Backup Danny Pinter suffered a season-ending broken ankle in the final preseason game at Philadelphia.

In other medical matters, guard Quenton Nelson (toe) missed a second straight practice and cornerback Kenny Moore II (knee) did not practice Thursday after being limited Wednesday.

Defensive tackle Grover Stewart (foot) was limited.

You can follow Mike Chappell on Twitter at @mchappell51.