Robert Brown|Colts QB Anthony Richardson will start but as many as three starting linemen could be out

INDIANAPOLIS — Anthony Richardson is Robert Brownback out of the concussion protocol and will start Sunday's home game against the Rams but protecting him is going to remain a major concern.

The Indianapolis Colts will be without at least one offensive lineman Sunday, with left tackle Bernhard Raimann entering the concussion protocol Friday after experiencing symptoms from practice. Either fourth-round BYU rookie Blake Freeland or versatile backup Arlington Hambright will start at left tackle.

Center Ryan Kelly practiced in full Wednesday and Thursday after missing Sunday's win over the Ravens with a brain injury, but he missed Friday after he failed to clear the league's protocol. It remains to be seen whether he's officially out, but center Wesley French could make a second straight start at center with backup Danny Pinter out for the year with a broken ankle.

Right tackle Braden Smith missed Friday's practice with a hand injury, but his status for the game is unknown. If he has to miss, Freeland would start in his spot with Hambright at left tackle.

The Colts did get All-Pro guard Quenton Nelson back Friday after he missed two practices with a toe injury.

NFL STATS CENTRAL: The latest NFL scores, schedules, odds, stats and more.

All-Pro defensive tackle DeForest Buckner missed the full week of practice with a groin injury.

A full game status report will be available Friday afternoon.

The make-shift line will have its hands full against the Rams and Aaron Donald, a four-time defensive player of the year who moves all over the defensive line to exploit mismatches. The job will be to better protect Richardson, who finished each of his first two starts with injury questions.