LOS ANGELES — As the dust settled on the Rams’ evaluation of their field goal unit after two more misses in Sunday’s victory over the New Orleans Saints, the team is poised to make at least one big change to its operation, and potentially two. On Tuesday, the Rams (6-2) signed veteran long snapper Jake McQuaide to the practice squad. A day later, they signed kicker Harrison Mevis to the practice squad, as well. Mevis will compete with incumbent kicker Joshua Karty for the job this week, head coach Sean McVay told reporters on Wednesday, while he expects McQuaide to take over from Alex Ward as the team’s long snapper this weekend against the San Francisco 49ers (6-3) if all goes according to...