In a statement Monday, Steelers' President Art Rooney II said the team plans to move deliberately to find a replacement for Bill Cowher. Tomlin, Minnesota's defensive coordinator, was scheduled for a second interview Tuesday and Grimm on Wednesday.
Rivera, Chicago defensive coordinator, is not available until the Bears play the Saints or, depending on the outcome of that game, until after the Super Bowl.
"It is our task to determine which one is the best candidate for the Pittsburgh Steelers at this point in time," Rooney said in a statement. "Our time frame remains as was stated at the beginning. We will conclude the search when we have found the best coach for the Pittsburgh Steelers."
Ken Whisenhunt, the Steelers' offensive coordinator, removed himself from the competition by accepting the job of head coach of the Arizona Cardinals. The team took Chan Gailey of Georgia Tech off the list.