When asked earlier this week if Bridgewater will ever play again, coach Mike Zimmer replied, "I honestly have no idea."
That being the case, Keenum will replace long-standing No. 2 QB Shaun Hill, who remains unsigned as a 37-year-old free agent.
After entering last season as Los Angeles' starter, Keenum lost the job in response to long stretches of action without finding the end zone. By midseason, the undermanned Rams offense was the league's least efficient.
Over 24 NFL starts and 26 appearances, Keenum has recorded a 58.4 completion rate, 24:20 TD-to-INT ratio and 78.4 passer rating.
Clearly overmatched as a starter, he's better suited to backing up Bradford.