"Diggs and I had talked over the last couple days very openly because I respect him so much," Spagnuolo told the St. Louis Post-Dispatch, calling the 11-year veteran "one of the classiest individuals."
Diggs, 33, signed with the Rams as a free agent before the 2010 season and finished with 37 tackles. He started 12 games but suffered a torn pectoral muscle that ended his season. Diggs started the first two preseason games this year but was replaced by Brady Poppinga on Friday against Kansas City.
Poppinga, 31, who played six seasons in Green Bay, appears to be the front-runner for a starting job.
"You want to get to the point where you're struggling to make decisions like today," Laurinaitis said.
Bradford won't be able to attend the ceremony, so another celebration will take place whenever he is able to attend.
Bradford's statue will join depictions of past Heisman Trophy winners Billy Vessels, Steve Owens, Billy Sims and Jason White.
The Associated Press contributed to this report.